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HomeMy WebLinkAboutChap9_FacGuidelines These facility guidelines are intended to guide development of all types of trail and bikeway facilities. The first section considers the necessary planning aspects of trail and bikeway systems design in general. The following section discusses general physical design guidelines. Subsequent sections provide physical design information for trails and specific classes of bikeway facilities. 9.1 Trail and Bikeway Planning Successfully implementing trail and bikeway systems involves careful planning that considers a number of issues, including setting up appropriate mechanisms to take advantage of trail and bikeway opportunities as they become available. Author and bicycle planning expert Susan Pinsof has perhaps described the process most succinctly: “A comprehensive, affordable approach to bicycle planning involves maximizing the usefulness of existing infrastructure by improving the safety of shared roadway space; using opportunities, such as available open space corridors for trails; creating more “bicycle-friendly” communities through planning, design and regulation; and addressing the need for bicycle-safety education and encouragement.” What Pinsof says about bikeway planning naturally applies to trail planning since pedestrians, equestrians and cyclists are likely to share the same trail facilities. In most cases, cities have tended to develop bicycle master plans as a mandated prerequisite to applying for bikeway facility funding. It is still fairly uncommon for cities to develop trail master plans. The City of Temecula, by developing a master plan for both of these systems in tandem, is likely to maximize the potential for a viable overall non-motorized transportation system because connections can be planned that benefit both systems and route redundancies can be avoided. This tandem approach should be more widely used. 9.1.2 Master Plan Process The basis for a community conducive to pedestrian, equestrian and bicycle use can be established by instituting appropriate policies through the development and and adoption of this trail and bikeway master plan. A program of physical improvements and workable implementation strategies that reflects local needs was developed as part of this master plan. A trail and bikeway master plan will be of little value if it is not part of an active and ongoing planning process that continually seeks to integrate pedestrian, equestrian and cycling considerations into all areas of local planning. Within this master plan, facility design guidelines have been tailored to local conditions, but are also consistent with national guidelines, such as the AASHTO Guide to Development of Bicycle Facilities. State guidelines are also referenced, specifically, Caltrans Highway Design Manual, Chapter 1000, Bikeway Planning and Design and the Caltrans Traffic Manual. Elements of these guidelines without relevance to the region have been excluded. 9.1.3 “Institutionalizing” Multi-Use Trail and Bikeway Planning Achieving implementation of this master plan will be greatly expedited by “institutionalizing” trail and bikeway planning, a concept first developed by Peter Lagerway as part of his efforts as the city of Seattle’s pedestrian and bicycle coordinator. The term refers to coordinating local planning and regulatory functions in the development of a program of improvements. Three elements are needed to institutionalize trail and bikeway planning on a local level: 1) a trail advisory committee; 2) a pedestrian and bicycle coordinator; and 3) committed public officials. 1) Public involvement can be promoted through the formation of a trail advisory committee as a new city committee, or as a subcommittee of an appropriate existing committee. Its primary benefit would be in providing an avenue for public participation and support. (A trails advisory committee was established during the preparation of Chapter Nine FACILITY GUIDELINES Facility Guidelines City of Temecula Page 9-2 Chapter 9 this master plan comprised of City officials, trail user group representatives and citizens.) 2) City government involvement can occur through the designation of a pedestrian, equestrian and bicycle coordinator. For a city the size of Temecula, this may be a part-time position, but this does not diminish its importance. Since a truly comprehensive trail and bicycle planning effort will involve many city departments including public works, parks and recreation, planning, schools and police, the pedestrian, equestrian and bicycle coordinator would be in a position to organize interdepartmental efforts and make certain that pedestrian, equestrian and bicycle concerns are integrated into other city activities in the planning stages, as well as coordinate with adjacent communities and jurisdictions. 3) The third aspect of institutionalization of trail and bicycle planning involves obtaining the commitment of public officials. Leadership for trail and bicycle improvements may already come from public officials, but even if it does not, officials will be more likely to be supportive if they can be certain their constituency wants a more pedestrian and bicycle-friendly community. (The involvement of city leaders in the advisory committee is a clear indication of public official commitment.) 9.1.4 Primary Planning Considerations The safety, efficiency and enjoyment of the trail and bike facilities by expected users should be the primary considerations employed in the planning of the new facilities. More specifically, such considerations should include the following: • Direct and convenient alignment to serve trip origins and destinations • Access to and from existing and planned trail and bicycle facilities • Avoiding abrupt facility discontinuity • Avoiding steep grades whenever possible • Adequate lighting and sight lines • Convenient bicycle parking at destinations • Adequate trail head facilities for equestrians • Adequate maintenance commitment 9.1.5 Integration with Other City Plans and Programs Trail and bikeway facility planning requires a high level of coordination because it is directly affected by the planning decisions of other City departments, as well as those of adjacent communities, the county, regional and state agencies. Land use, zoning, street design, open space and park planning all affect how trail and bicycle-friendly a community can be. For example, land use patterns affect walking, horseback riding and cycling by determining the locations of trip origins and destinations by such means as creating areas of employment and housing densities sufficient to sustain trails and bikeway facilities, or by providing a balance of housing and jobs by encouraging multi-use development. Trail access or bicycle parking facilities can often be included in developments at a low cost. Also, the provision of better access and connections between developments for pedestrians, equestrians and cyclists may be more easily provided if the need is understood and articulated as early as possible in the planning process. Effective trail and bikeway planning may require review of regional transportation plans, local street plans, park and open space plans and even site plan review. Transportation plans provide opportunities for low cost improvements to be designed into subsequent projects. Local street plans provide opportunities to implement changes that make streets more conducive to walking, horseback riding and cycling using techniques such as “traffic calming” (See Section 9.3.21). Park and open space planning provide opportunities to acquire greenways and to build multi-use trails. Site plan review provides opportunities to ensure that project design accommodates walkers, eques Chapter 9 Page 9-3 Multi-Use Trails and Bikeways Master Plan trians and cyclists through the provision of improvements such as access or parking facilities and that the project’s vehicular traffic does not decrease the safety of walkers, equestrians and cyclists of adjacent facilities. 9.1.6 Education and Encouragement Education and encouragement of walking, horseback riding and cycling are important elements of any trail and bikeway planning effort and can occur through instructional venues such as school curricula and through the efforts of large employer-based transportation programs. There is no shortage of educational materials available through a number of private and government organizations. The dissemination of meaningful information can also be augmented by the participation of local businesses such as bike and tack shops, especially since they have a vested interest in promoting safe cycling and riding in Temecula. 9.1.7 Regulating Land Use and Community Design to Benefit Non-Motorized Transportation Land use and design options are largely determined by regulatory functions that, in turn, help to define community character and functionality. These regulatory functions such as subdivision regulations, zoning requirements and developer exactions are also often used to set requirements for amenities in new development projects. These same regulations can be used to help define development patterns more conducive to walking, horseback riding and cycling such as incorporating more mixed use, higher densities and connections between communities and land uses. Street patterns and hierarchy can greatly affect average daily (motor vehicle) trips (ADTs), connectivity and motor vehicle speeds, which in turn positively or negatively affect walking and cycling. Street design can be modified to discourage high motor vehicle speeds and to provide width for a bike lane. Linear open space can become land for greenway routes that benefit all non-motorized users, such as walkers, cyclists and equestrians. Though prioritization of trail and bikeway projects is defined by State and local decisions, it is Federal funding and policies that currently encourage the use of transportation funds for pedestrian and bicycle projects. However, Federal funding can not be counted upon as a reliable source for the foreseeable future since it depends on the political nature of legislative action. Trail and bikeway planning can not sustain itself on the occasional Federal grant. Future local implementation will more likely depend on instituting trail and bikeway improvements as part of infrastructural projects, which is when they are most cost-effective. Similarly, the most economical way to include trail and bikeway facilities in private development is through initial project planning and design, not as an afterthought. Ordinances can be written that trail and bikeway systems be included as part of new developments. An effort should be made to show developers that such requirements are worthwhile because they create well-established marketing advantages gained from providing pedestrian and bicycle amenities. Ordinances can also require bicycle amenities such as bicycle parking, showers and lockers at employment sites. In all cases, a trail and bikeway master plan is important for establishing priorities for such public/private projects. Review of developments for transportation impacts should address how on-site bicycle facilities are planned. Bicycle storage racks should be provided at commercial facilities at locations convenient to building entrances and covered from the elements. This is especially important at retail and service establishments. At employment sites, secure bicycle racks and/or lockers should be provided. Facility Guidelines City of Temecula Page 9-4 Chapter 9 Requiring developments near transit centers to provide access pathways to these centers as part of urban in-fill may improve multi-modal connections for pedestrians and cyclists alike. Other developers should contribute to trail and bikeway master plan implementation projects in newly developing areas. 9.2 Unpaved Multi-Use Trail Facilities General Physical Guidelines In general, many of the physical parameters desirable for unpaved trails are similar to those used for Class 1 bicycle facilities. In the following sections, the limiting criterion for factors such as design speed and curve radii is often the capabilities of cyclists due to the speeds bicycles are capable of attaining compared to other trail user types. Most of the bicycles sold today are mountain bikes designed for use on unpaved surfaces and come equipped with wide tires and low gearing and most recreational cyclists ride this type of bicycle. Unpaved trails are not likely to attract many commuting cyclists, but the trails may experience some utility use if they provide convenient shortcuts between popular destinations where such routes would not otherwise exist. A cursory review of the sections of this chapter on unpaved trail and Class 1 bikeway design guidelines will reveal many similarities. However, there are differences and they can be significant. In many cases, there are no specific rules for unpaved trail design as there are for bikeway design. This is because trails serve many purposes in many settings and a codified set of design criteria can not fulfill all trail design situations. The paramount concern for the designer should be safety. 9.2.1 Width and Clearance Unpaved trail width is a primary design consideration, but there are no definitive minimums. Unpaved trails as narrow as two feet wide can and do accommodate even equestrians and cyclists if there is adequate horizontal clearance, but more than minimal use mandates a greater width. The width of a trail should be a function of the amount and mix of trail user types expected, the available horizontal and vertical clearances and the horizontal and vertical alignment of the trail bed. Under certain conditions it may be necessary or desirable to increase the width, for examples, because of substantial equestrian or bicycle volume, probable shared use with joggers and other pedestrians, use by maintenance vehicles, steep grades, or where users will be likely to ride or walk two abreast. Reduced widths are acceptable on secondary access trails due to their generally short length and low volumes. However, width adequate for safety should always be employed. One-directional trail facilities are not generally recommended since they will almost certainly be used as two-way facilities due to the difficulty of enforcing them. A minimum of two feet horizontal clearance from the edge of either side of the trail bed is desirable from trees, poles, walls, fences, guardrails, or other lateral obstacles. Where available and where higher use use volumes call for it, a wider graded area on either side of the trail can serve as a separate jogging path or passing zone. In most cases, vertical clearance to overhead obstructions should be a minimum of eight feet. Vertical clearance may need to be greater to permit passage of maintenance vehicles and, in undercrossings and tunnels, a clearance of 10 feet is desirable for adequate vertical shy distance. Where equestrian use is expected, vertical clearance should be at least 10 feet. 9.2.2 Sight Distance To provide trail users with an opportunity to see and react to the unexpected, a trail should be designed with adequate stopping sight distance. Of all user types, cyclists have the longest stopping distance. The distance required to bring a bicycle to a full controlled stop is a function of the cyclist’s perception and brake reaction time, the initial speed of the bicycle, the coefficient of friction between the tires and the trail surface and the braking ability of the bicycle. Unpaved trail surfaces surfaces tend to have lower friction coefficients than paved Chapter 9 Page 9-5 Multi-Use Trails and Bikeways Master Plan surfaces, but this is not a given and most bicycles sold today have wide, high traction tires. In general, wherever the trail bed’s vertical and horizontal alignment may allow higher speeds than prudent, sight distance should be carefully evaluated and maximized. In most cases, problems occur on trail segments with steeper grades or where brush is allowed to grow right up to the trail bed, obscuring the trail beyond a short distance away. A trail user education program emphasizing reasonable speeds, trail etiquette and the characteristics of other user types is highly recommended. 9.2.3 Steep Grades Grades on trails can be somewhat steeper compared to what is recommended for Class 1 bikeways. Grades are not an impediment to the design, construction and use of trails and, for some users, even add to the appeal of a route. However, steeper grades should be kept to a minimum, especially on long inclines. Long grades greater than eight percent are undesirable because the ascents are difficult for many users and the descents cause some users to exceed the speeds at which they are competent. Where terrain dictates, grades over eight percent and less than 500 feet long are acceptable when a higher sight distance is used and additional width is provided. Crushed stone surfaces on trails with grades steeper than three percent may not be practical for bicycle use. 9.2.4 Pavement Structure Under most circumstances, local soil is suitable for unpaved trail surfacing. Where unsatisfactory soils can be anticipated, a soil investigation should be conducted to determine the load-carrying capabilities of the native soil and the need for any special provisions. In the event full-size emergency vehicle access is needed for a trail segment, it should be designed to sustain without damage the wheel loads of occasional emergency, patrol, maintenance and other motor vehicles that are expected to use or cross the trail. Full-size emergency vehicle use is unlikely to be a factor on anything but dirt roads designated as trails. Where such existing dirt maintenance access roads are to be designated as trails, the existing surface should be more than adequate for all non-motorized users. It is important to construct and maintain a relatively smooth riding surface on unpaved trails. On the other hand, skid resistance qualities should not be sacrificed for the sake of smoothness. Root barriers should be used where necessary to prevent vegetation from encroaching onto the trail bed or the adjacent vegetation cut back. Unpaved trail crossings of highways or driveways should be paved a minimum of 10 feet on each side of the crossing to reduce the amount of trail surface grit being scattered onto the roadway by trail users or maintenance vehicles. 9.2.5 Drainage The necessity for drainage structures can usually be avoided by appropriately grading the trail. A recommended minimum cross slope of two percent adequately provides for drainage. Sloping in one direction instead of crowning is preferred. A smooth surface helps to prevent water ponding and ice formation. Where an unpaved trail is constructed on the side of a hill, no ditches or berms should be placed on the sides of the trail to intercept the hillside drainage. Instead, the trail bed should be designed with a uniform outward (downhill) slope of three to five percent. The goal is sheet flow across the full distance of the sloped trail segment. In general, sheet flow across the trail is desirable and point concentration should be avoided. Where necessary, catch basins with drains should be provided to carry the intercepted water under the path. To prevent erosion adjacent to the trail, the design should include considerations for preserving the natural ground cover. Seeding or mulching of adjacent slopes, swales and other erodible areas should be included in the design plans. Facility Guidelines City of Temecula Page 9-6 Chapter 9 9.2.6 Structures A bridge, drainage facility or facility on a highway bridge may be necessary to provide unpaved trail continuity. Bridge structures should be appropriate to the expected use and setting. On new structures, the minimum clear width should be the same as the approach trail and the desirable clear width should include the minimum two foot wide clear areas. Carrying the clear areas across the structures has two advantages. First, it provides a minimum horizontal shy distance from the railing or barrier, and second, it provides needed maneuvering space to avoid conflicts with other users stopped on the bridge. Where necessary, access by emergency, patrol and maintenance vehicles should be considered in establishing the design clearances of structures on unpaved trails. Similarly, vertical clearance may be dictated by occasional motor vehicles using the path. Where practical, a vertical clearance of 10 feet is desirable for adequate vertical shy distance, and at least 10 feet where equestrian use is likely. An approach apron of a material similar to the bridge decking should be installed on either side of the bridge deck. This apron should be of a length of approximately half the bridge width, with a minimum of two feet to prevent users from scattering trail grit onto the bridge surface. Railings, fences, or barriers on both sides of a trail structure should be a minimum of 4.5 feet high. Smooth rub rails should be attached to the barriers at handlebar height of 3.5 feet. However, where appropriate, railings may not be necessary. This is a judgment call based on expected use levels, types of users and the length and height of the bridge. Bridges designed exclusively for non-motorized traffic may be designed for pedestrian live loading. On all bridge decks, special care should be taken to ensure that bicycle-safe expansion joints are used. Joints should run across the bridge, never parallel to it. 9.2.7 Maintenance Priorities When properly designed, unpaved trails require little maintenance. However, even the best designed trails will usually require some regrading each spring after the winter rainy season, though this can usually be accomplished with hand tools or small power equipment. Maintenance will usually consist of deberming, or removing the displaced soil that collects at the downhill edge of the trail over time, preventing water from flowing across and off the trail. Another task is filling and packing down any ruts or holes once the cause of the problem has been determined and eliminated. Any trail that requires more than minimal annual regrading should be evaluated to determine what is causing the erosion. Water flowing parallel to the trail bed causes the majority of erosion problems. When evaluating trail erosion, care should be taken to examine the trail for a considerable distance uphill to find where the water begins to concentrate and to resolve the issue beginning at that point. Most unsolvable problems are due to poor initial design. If a trail develops a drainage problem that can not be cured, is should be rerouted. If the trail can not be rerouted, erosion control devices should be installed. Where they are necessary, devices involving slight grade changes such as rolling grade dips and knicks should be used. Solid barriers such as water bars are recommended only as a last resort. The availability of a forum through which citizens can conveniently notify the proper city authority of trail facility problems or shortcomings is recommended. The City could make available via its web site, for example, a service request form to allow citizens to report trails problems. Volunteer trail maintenance programs have been successfully employed at numerous national parks, national forests and state parks. Such a program could significantly reduce maintenance costs for the City and provide a sense of ownership for Chapter 9 Page 9-7 Multi-Use Trails and Bikeways Master Plan trail users. Volunteer programs would probably be most successful if implemented through established user groups. Maintenance issues larger than what the volunteers can accomplish would be reported to the City. This is the model currently in use in many regional parks. 9.2.8 Horizontal Separation from Roadways Non-motorized unpaved trail facilities are physically separated from roadways. However, where an unpaved trail facility must be considered within a roadway right-of-way, a wide separation between the trail and the adjacent highway is desirable to confirm for both the non-motorized trail user and the motorist that the trail functions as an independent route for trail users. In addition to physical separation, landscaping or other visual buffer is desirable. When this is not possible and the distance between the edge of the roadway and the trail is less than five feet, a suitable physical divider should be considered. Such dividers serve both to prevent trail users from making unwanted movements between the trail and the highway shoulder, for the protection of trail users from motor vehicles and to reinforce the concept that the trail is an independent facility. Where used, the divider should be a minimum of 4.5 feet high, to prevent trail users from toppling over it and it should be designed so that it does not become an obstruction or traffic hazard in itself. 9.2.9 Design Speed Available guidelines for multi-use unpaved facilities are limited. In general, the coefficient of friction used in calculating curve radii and a factor in determining bicycle design speed should be used, but considerably reduced. This reduction in friction affects all situations where traction is important, especially on grades. It is suggested that friction factors be reduced by 50 percent below paved standards to allow a sufficient margin of safety. For a multi-use unpaved trail, the design speed should be based on the characteristics of cyclists since they are likely likely to be the fastest user type. The speed that a trail user travels is dependent on several factors, including the type and condition of the bicycle, horse or trail user, the condition and location of the trail and the speed and direction of the wind. Unpaved trails should be designed for a speed that is at least as high as the preferred speed of the faster cyclists, or 15 mph. Where grades dictate, the design speed should be raised to 25 mph. Although data are not available for unpaved surfaces, bicycles have a higher tendency to skid on unpaved surfaces. 9.2.10 Horizontal Alignment Especially on single-track trails, it is likely that small radius curves will be needed due to right-of-way restrictions, topographical obstacles, or other considerations. This can be somewhat compensated for by widening the trail bed through tight curves or installing curve warning signs where appropriate, especially uphill of the curve. Tight curves can actually be an asset to a technically challenging trail by slowing down the faster users. For a multi-use unpaved trail, the minimum negotiable radius of curvature should be based on the characteristics of cyclists since they are likely to be the fastest user type with the smallest contact point with the trail surface. The minimum negotiable radius of curvature depends upon speed, surface type, roughness and condition, tire type and condition and whether the surface is wet or dry, but horizontal curvature design should take into account lower coefficients of friction. Unpaved trails can vary considerably in terms of what the smallest radius of curvature should be. There is no fixed minimum radius of curvature for unpaved trails due to the variety of situations possible, but curves generally become tighter with the steepness of the terrain. When traversing a slope, climbing turns having a consistent grade throughout the turn should be used on slopes of up to seven percent. Switchbacks should be used on slopes steeper than seven percent. Facility Guidelines City of Temecula Page 9-8 Chapter 9 9.2.11 Switchbacks In areas of steep terrain, switchbacks may be the only solution to traversing changes in elevation. Switchbacks differ from climbing turns in that they have a level “table” at the apex of the turn from which the two legs of the trail ascend and descend. A grade of eight percent is acceptable for a distance of no more than 100 feet on these legs. Switchback radii will probably be defined by the local topography, but they should be larger than normally employed for pedestrian facilities to allow for cyclists to be able to safely make the turns without having to dismount. Pavement width should be as wide as possible to allow ascending cyclists room to walk their bicycles when necessary. The switchbacks should be completely visible from the next uphill turn. The tables at the end of each switchback should be fairly large for the benefit of cyclists unable to slow down quickly enough to make the turn and as a place for users to stop if desired. In particularly steep areas, curve radii may be enlarged, the trail widened and runout areas provided. Rock or log barriers should be installed along the inside of the switchback radius to discourage shortcuts and appropriate warning signing should be placed at the top of the descent. The signage may recommend that inexperienced cyclists dismount and that uphill users have the right-of-way. In areas of erosive soils, it is also advisable to install signage requiring cyclists to dismount when traversing the switchbacks. 9.2.12 Intersections Intersections with roadways are important considerations in unpaved trail design. If alternate locations for a trail are available, the one with the most favorable intersection conditions should be selected. For crossings of freeways and other highspeed, high-volume arterials, a grade separation structure may be the only possible or practical treatment. Unless bicycles are prohibited from the crossing highway, providing for turning movements must also be considered. considered. When intersections occur at grade, a major consideration is the establishment of right-of-way. The type of traffic control to be used (signal, stop sign, yield sign, etc.) and locations, should be provided in accordance with the Caltrans Traffic Manual. Sign type, size and location within the highway right-of-way should also be in accordance with the Caltrans Traffic Manual. Care should be taken to ensure that trail and roadway signs are located so that motorists and trail users are not confused by each other’s signs. Other means of alerting trail users of a highway crossing include grade changes, changing surfaces at the approach, a fairly abrupt change in direction on the approach combined with a colorful partial barrier, and signage, which can and should be used with any of the other warning methods. Devices installed to prohibit motorists from entering the trail can also assist with alerting trail users to roadway crossings. It is preferable that the crossing of a trail and a highway be at a a location away from the influence of intersections with other highways. Controlling vehicle movements at such intersections is more easily and safely accomplished through the application of standard traffic control devices and normal Rules of the Road. Where physical constraints prohibit such independent intersections, the crossings may be at or adjacent to a pedestrian crossing. Right-of-way should be assigned and sight distance should be provided so as to minimize the potential for conflict resulting from unconventional turning movements. At crossings of high volume, multi-lane arterial highways where signals are not warranted, consideration should be given to providing a median refuge area for trail users, though this is not desirable for horses. When trails terminate at existing roadways, it is important to make this clear well before the roadway is reached. Care should be taken to properly design the terminals to transition the trail users Chapter 9 Page 9-9 Multi-Use Trails and Bikeways Master Plan into a safe diverging situation. Colorful partial barriers may also be used. Appropriate signage is necessary to warn and direct both trail users and motorists regarding these transition areas. Trail intersections and approaches should be on relatively flat grades. Stopping sight distances at intersections should be adequate and warning signage should be provided to permit trail users to easily stop before reaching the intersection, especially on downgrades. Ramps for curb cuts at intersections should be the same width as the trail. Curb cuts and ramps should provide a smooth transition between the trail and the roadway. 9.2.13 Signing and Marking Adequate signing and marking are essential on trails, especially to alert trail users to potential conflicts and to convey regulatory messages to both trail users and motorists at highway intersections. In addition, guide signing, such as to indicate directions, destinations, distance, route numbers and names of crossing streets, should be used in the same manner as they are used on highways, though the signage can of more appropriate size and character. In general, uniform application of traffic control devices throughout a trail system will tend to encourage proper trail behavior. 9.2.14 Lighting Fixed-source lighting reduces conflicts along the trails and at intersections. In addition, lighting allows the trail user to see the trail direction, surface conditions and obstacles. Lighting for trails is desirable where riding at night is expected, such as trails serving college students or commuters and at highway intersections. Another possibility is where a significant number of users may be on the trail after dark, such as adjacent to a historical or entertainment district. At the minimum, lighting should be considered through underpasses or tunnels and where nighttime security may be a problem. Depending on the location, average maintained horizontal illumination levels of 5 to 22 lux should be considered. Light standards (poles) should meet the recommended horizontal and vertical clearances. Luminaires and standards should be at a scale appropriate for a pedestrian or bicycle path. (See Section 1003.6 of the Caltrans Highway Design Manual.) In most cases, lighting will be out of character with an unpaved trail system except for the exceptions listed above. 9.2.15 Barriers to Motor Vehicle Traffic Unpaved trails may need some type of physical barrier at highway intersections and bridges to prevent unauthorized motor vehicles from using the trail facilities. One method is a lockable, removable post to permit entrance by authorized vehicles that is permanently reflectorized for nighttime visibility and painted a bright color for improved daytime visibility. When more than one post is used, a five foot spacing is desirable. Wider spacing can allow entry to motor vehicles, while narrower spacing may prevent entry by adult tricycles and bicycles with trailers. An alternate method of restricting motor vehicles is is to split the entry into two five foot sections separated by low landscaping. Emergency vehicles can still enter, if necessary, by straddling the landscape. The higher maintenance costs associated with landscaping should be considered, however, before this alternative method is selected. 9.3 On-Street Bikeway General Physical Guidelines The following sections cover physical design guidelines applicable to all bikeway facility types. Guidelines specific to Class 1, 2 and 3 facilities are covered in subsequent sections. Facility Guidelines City of Temecula Page 9-10 Chapter 9 Recommended Pavement Widths* Table 9-1 Posted Speed Limit Urban w/Parking Urban w/o Parking Rural 1,200 to 2,000 ADTs <30 mph 12 ft. SL 11 ft. SL 10 ft. SL 31-40 mph 14 ft. SL 14 ft. SL 12 ft. SL 41-50 mph 15 ft. SL 15 ft. SL 3 ft. SH >50 mph NA 4 ft. SH 4 ft. SH 2,000 to 10,000 ADTs <30 mph 14 ft. SL 12 ft. SL 12 ft. SL 31-40 mph 14 ft. SL 14 ft. SL 3 ft. SH 41-50 mph 15 ft. SL 15 ft. SL 4 ft. SH >50 mph NA 6 ft. SH 6 ft. SH More than 10,000 ADTs or Trucks over 5% <30 mph 14 ft. SL 14 ft. SL 14 ft. SL 31-40 mph 14 ft. SL 4 ft. SH 4 ft. SH 41-50 mph 15 ft. SL 6 ft. SH 6 ft. SH >50 mph NA 6 ft. SH 6 ft. SH Notes: *Primarily applicable to Class 3 and "Undesignated" routes. SH = Shoulder SL = Shared Lane Shared lane is acceptable for volumes less than 1,200 ADTs. Provide 8' shoulder for volumes greater than 10,000 ADTs. 9.3.1 Bikeway Pavement Width At a minimum, all roadway projects shall provide sufficient width of smoothly paved surface to permit the shared use of the roadway by bicycles and motor vehicles. Table 9-1 is based on the FHWA publication, Selecting Roadway Design Treatments to Accommodate Bicycles. Pavement widths represent minimum design treatments for accommodating bicycle traffic. These widths are based on providing sufficient pavement for shared use by bicycle and motor vehicle traffic and should be used on roadway projects as minimum guidelines for bicycle compatible roads. Considerations in the selection of pavement width include traffic volume, speed, sight distance, number of large vehicles (such as trucks) and grade. The dimensions given in Table 9-1 for shared lanes are exclusive of the added width for parking, which is assumed to be eight feet. On shared lanes with parking, the lane width can be reduced if parking occurs only intermittently. On travel lanes where curbs are present, an additional one foot is necessary. Chapter 9 Page 9-11 Multi-Use Trails and Bikeways Master Plan On very low volume roadways with ADTs of less than 1,200, even relatively high speed roads pose little risk for cyclists since there will be high probability that an overtaking motor vehicle will be able to widely pass a bicycle. When an overtaking car is unable to immediately pass a bicycle, only a small delay for the motorist is likely. These types of roadways are jointly used by both cyclists and motorists in a safe manner and widening of these roads is not usually recommended. Costs of providing widening of these roads can seldom be justified based on either capacity or safety. Similarly, moderately low volume roadways with ADTs between 1,200 and 2,000 generally are compatible for bicycle use and will have little need for widening. However, since there is a greater chance of two opposing cars meeting at the same time as they must pass a cyclist, providing some room at the outside of the outer travel lane is desirable on faster speed roadways. roadways. On low speed roadways, motorists should be willing to accept some minimal delay. With ADTs from 2,000 to 10,000, the probability becomes substantially greater that a vehicle overtaking a bicycle may also meet another oncoming vehicle. As a result, on these roads, some room at the edge of the roadway should be provided for cyclists. This additional width should be two to three feet added to a typical 11 foot outer travel lane. At low speeds, such as below 25 mph, little separation is needed for both a cyclist and a motorist to feel comfortable during a passing maneuver. With higher speeds, more room is needed. At volumes greater than 10,000 ADTs, vehicle traffic in the curb lane becomes almost continuous, especially during peak periods. As a result, cyclists on these roadways require separate space to safely ride, such as a Class 2 facility. In addition, improvements to the roadway edge and the shoulder area will be valuable for motorists as well. Caltrans guidelines for highways recommend that a full eight foot paved shoulder be provided for State highways. On highways having ADTs greater than 20,000 vehicles per day, or on which more than five percent of the traffic volume consists of trucks, every effort should be made to provide such a shoulder for the benefit of cyclists, to enhance the safety of motor vehicle movements and to provide “break down” space, as well as a Class 2 facility. Otherwise, the highway should probably not be designated as a bicycle facility. 9.3.2 Sight Distance Roadways with adequate sight distance will allow a motorist to see, recognize, decide on the proper maneuver and initiate actions to avoid a cyclist. Adequate decision sight distance is most important on high speed highways and narrow roadways where a motorist would have to maneuver out of the travel lane to pass a cyclist. The pavement widths given in Table 9-1 are based on the assumption that adequate sight distance is available. In situations where there is not adequate sight distance, the provision of additional width may be necessary. 9.3.3 Truck Traffic Roadways with high volumes of trucks and large vehicles, such as recreational vehicles, need additional space to minimize cyclist/motorist conflicts on roadways. Additional width will allow overtaking of cyclists by trucks with less maneuvering. Additionally, overtaking by a truck will exert less lateral force from truck drafts and provide greater sight distance for following vehicles. Although there is no established threshold, additional space should be considered when truck volumes exceed five percent of the traffic mix, or on roadways that serve campgrounds, or where a high level of tourist travel is expected using large recreational vehicles. Where truck volumes exceed 15 percent of the total traffic mix, widths shown on the table should be increased by a minimum of one foot. Facility Guidelines City of Temecula Page 9-12 Chapter 9 9.3.4 Steep Grades Steep grades influence overtaking of cyclists by motorists. Cyclists climbing steep grades are often unsteady (wobbly) and may need additional width. Also, the difference in speed between a slow, climbing cyclist and a motor vehicle results in less time for the driver to react and maneuver around a cyclist. The slowing of a motor vehicle on a steep grade to pass a cyclist can result in a diminished level of service. 9.3.5 Unavoidable Obstacles Short segments of roadways with multiple unavoidable obstacles that result in inadequate roadway width are acceptable on bicycle compatible roadways if mitigated with signing or striping. Typical examples include bridges with narrow widths and sections of roadway that cannot be widened without removing significant street trees. These conditions preferably should not exist for more than a quarter of a mile, or on high speed highways. “Zebra” warning striping should be installed to shift traffic traffic away from the obstacle and allow for a protected buffer for bicycle travel. In situations where a specific obstacle such as a bridge abutment can not be avoided, a pavement marking consisting of a single six inch white line starting 20 feet before and offset from the obstacle can also be used to alert cyclists that the travel lane width will soon narrow ahead. (See Section 1003.6 of the Caltrans Highway Design Manual for specific instructions.) In either situation, where bicycle traffic is anticipated, a “SHARE THE ROAD” sign should be used to supplement the warning striping. On longer sections of roadway that are irrevocably narrow, edge striping should be employed to narrow the travel lane and apportion pavement space for a partial shoulder. In situations where even these measures may not provide adequate roadway space for cyclists, it is recommended that an alternate route be designated. 9.3.6 Pavement Design Though wider tires are now very common and bicycle suspension systems are becoming increasingly prevalent, bicycles still require a riding surface without significant obstacles or pavement defects because they are much more susceptible to such surface irregularities than are motor vehicles. Asphalt is preferred over concrete where shoulders are employed. The outside pavement area where bicycles normally operate should be free of longitudinal seams. Where transverse expansion joints are necessary on concrete, they should be saw cut to ensure a smooth transition. In areas where asphalt shoulders are added to existing pavement, or where pavement is widened, pavement should be saw cut to produce a tight longitudinal joint to minimize wear and expansion of the joint. 9.3.7 Raised Roadway Markers Raised roadway markers such as reflectors or rumble strips should not be used on roadway edges where bicycles are most likely to operate because they are a surface irregularity that can be hazardous to bicycle stability. Painted stripes or flexible reflective tabs are preferred. In no case should strips of raised reflectors that are intended to warn motorists to reduce vehicle speeds prior to intersections be allowed to cross through the bicycle travel lane. 9.3.8 Utilities Because bicycles are much more sensitive to pavement irregularities than motor vehicles, utility covers should be adjusted as a normal function of any pavement resurfacing or construction operations. Failure to do so can result in the utility cover being sunken below the paving surface level which creates a hazard experienced cyclists refer to as “black holes.” Also, it is common practice to excavate trenches for new utilities at road edges, in the same location as bicycle facilities. When such trenching is completed, care should be given to replacing the full surface of the bicycle lane from Chapter 9 Page 9-13 Multi-Use Trails and Bikeways Master Plan the road edge to the vehicle travel lane instead of narrow strips that tend to settle or bubble, causing longitudinal obstructions. Replacement of the bike lane striping should also be required. 9.3.9 Drainage Facilities Storm water drainage facilities and structures are usually located along the edge of roadways where they often present conflicts with cyclists. Careful consideration should be given to the location and design of drainage facilities on roadways with bicycle facilities. All drainage grate inlets pose some hazard to bicycle traffic. The greatest hazard comes from stream flow drainage grates which can trap the front wheel of a bicycle and cause the cyclist to lose steering control, or have the narrow bicycle wheels drop into the grate. A lesser hazard is caused by cyclists swerving into the lane of traffic to avoid any type of grate or cover. Riding across any wet metal surface increases the chances of a sudden slip fall. Only a “bicycle-safe” drainage grate with acceptable hydraulic characteristics should be used. The inlet grate should be used in all normal applications and should be installed flush with the final pavement. Where additional drainage inlet capacity is required because of excessive gutter flow or grade (greater than two percent), double inlets should be considered. Depressed grates and stream flow grates should not be used except in unique or unusual situations which require their use and only outside the lane sharing area. Where necessary, depressed grates should only be installed on shoulders six feet wide or greater. Where projects offer the possibility for replacement of stream flow grates located in the lane sharing area, these grates should be replaced with the “bicycle-safe” grate. When roads or intersections are widened, new bicycle-safe drainage grates should be installed at a proper location at the outside of the roadway, existing grates and inlet boxes should be removed and the roadway reconstructed. Drainage Drainage grate extensions, the installation of steel or iron cover plates or other “quick fix” methods which allow for the retention of the subsurface drain inlet are unacceptable measures since they will create a safety hazard in the portion of the roadway where cyclists operate. Manholes and covers should be located outside of the lane sharing area wherever possible. Utility fixtures located within the lane sharing area, or any travel lane used by bicycle traffic, should be eliminated or relocated. Where these fixtures cannot be avoided, the utility fixture cover should be made flush with the pavement surface. 9.3.10 Combination Curb and Gutter These types of curbs reduce space available for cyclists. The width of the gutter pan should not be used when calculating the width of pavement necessary for shared use by cyclist. On steep grades, the gutter should be set back an additional one foot to allow space to avoid high speed crashes caused by the longitudinal joint between the gutter pan and pavement. Where the combination curb and gutter is used, pavement width should be calculated by adding one foot from the curbed gutter. 9.3.11 Bridges Bridges provide essential crossings over obstacles such as rivers, rail lines and high speed roadways, but they have been almost universally constructed for the expedience of motor vehicle traffic and often have features that are not desirable for bicycling. Among these features are widths that are narrower than the approach roadways (especially when combined with relatively steep approach grades), low railings or parapets, high curbs and expansion joints that can cause steering problems. Though sidewalks are generally not recommended for cycling, there are limited situations such as long or narrow bridges where designation of the sidewalk as an alternate bicycle facility can be beneficial to cycling, especially when compared to riding in the narrow bridge roadway. This is only recommended where the appropriate curb Facility Guidelines City of Temecula Page 9-14 Chapter 9 cuts, ramps and signage can also be included. Using the bridge sidewalk as a bicycle facility is especially useful where pedestrian use is expected to be minimal. Appropriate signage directed to all potential users should be installed so that they will be aware of the shared use situation. Bridge railings or barrier curb parapets where bicycle use is anticipated should be a minimum of 4.5 feet high. • Modifications of Narrow Bridges Over Rivers and Highways Short of wholesale replacement of the existing narrow bridges over rivers and highways, there are a few measures to substantially improve safety for cyclists. Signage warning motorists of both the presence of cyclists and the minimal bridge width should be installed at the bridge approaches. “Zebra” warning stripe areas should be painted along high curbs to deter cyclists from riding too close to them which can result in the pedal hitting these high curbs, causing an accident. This situation is of particular concern since the cyclist will want to stay as far to the right as possible to avoid passing motor vehicles traffic, even though riding far to the right increases the chances of hitting the high curb. Though the first alternative mentioned above, bridge replacement, is the preferred alternative for bridges that are too narrow, it is the least likely to occur due to cost. A second alternative is to direct cyclists to alternate, safer routes, but this will not always be practical since highway and river crossing points are usually limited in number and considerable distances apart. In any case, these other crossing points may well have similar width restrictions. A third alternative is to build separate bridges for cyclist and pedestrian use. Where access warrants a workable solution, this could be a cost-effective long-term solution compared to rebuilding the motor vehicle bridge. These additional bridges could be built adjacent to the motor vehicle bridges, or be installed well away from them, depending upon where best to conveniently accommodate cyclists and pedestrians, who would also undoubtedly use such facilities. An advantage to constructing the bridges away from the motor vehicle bridges is that only one bridge would be needed since building bicycle/pedestrian bridges immediately adjacent to existing motor vehicle bridges would require constructing two one-way spans, one on each side of the roadway, for optimum user safety. If sidewalk widths are sufficient, directing cyclists to use the sidewalks and installing ramps at the bridge ends is a possible solution. In general, sidewalks are not recommended as a cycling venue and riding on sidewalks is illegal, but in cases where narrow bridges are not expected to be rebuilt for an extended period of time, this may be a reasonable alternative. If possible, a railing should be installed between the roadway and the sidewalk. Finally, it should be noted that all the other alternatives are inherently inferior to the first alternative of rebuilding narrow bridges in terms of safety, and should only be considered where the first alternative can not be implemented. Of course, the preferred methodology is to consider bikeway facilities on bridges prior to construction. 9.3.12 Traffic Control Devices As legitimate users of California’s roadways, cyclists are subject to essentially the same rights and responsibilities as motorists. In order for cyclists to properly obey traffic control devices, those devices must be selected and installed to take their needs into account. All traffic control devices should be placed so they can be observed by cyclists who are properly positioned on the road. This includes programmed visibility traffic signal heads. Chapter 9 Page 9-15 Multi-Use Trails and Bikeways Master Plan • Traffic Signals and Detectors Traffic-actuated signals should accommodate bicycle traffic. Detectors for traffic-activated signals should be sensitive to bicycles, should be located in the cyclist’s expected path and stenciling should direct the cyclist to the point where the bicycle will be detected. Since detectors can fail, added redundancy in the event of failure is recommended in the form of pedestrian push buttons at all signalized intersections. These buttons should be mounted in a location which permits their activation by a cyclist without having to dismount. Buttons are also important because it is increasingly common for bicycles to be made of so little ferrous metals that they may not be detectable by many currently installed types of loop detectors. Where left turn lanes are provided and only protected left turns are allowed, bicycle sensitive loop detectors should be installed in the left turn lane, or a pedestrian style push button should be provided that is accessible to the cyclist in the median immediately adjacent to the turn lane to permit activation of the left turn phase. Where moderate or heavy volumes of bicycle traffic exist, or are anticipated, bicycles should be considered in the timing of the traffic signal cycle as well as in the selection and placement of the traffic detector device. In such cases, short clearance intervals should not be used where cyclists must cross multi-lane streets. According to the 1991 AASHTO Guide for the Development of Bicycle Facilities, a bicycle speed of 10 mph and a perception/reaction time of 2.5 seconds can be used to check the clearance interval. Where necessary, such as for particularly wide roadways, an all-red clearance interval can be used. In general, for the sake of cyclist safety, protected left turns are preferred over unprotected left turns. In addition, traffic signal controlled left turns are much safer for cyclists than left turns at which motorists and cyclists must simply simply yield. This is because motor vehicle drivers, when approaching an unprotected left turn situation or planning to turn left at a yield sign, tend to watch for other motor vehicles and may not see an approaching cyclist. More positive control of left turns gives cyclists an added margin of safety where they need it most. • Signing When designating a bicycle route, the placement and spacing of signs should be based on the Caltrans Traffic Manual and Highway Design Manual. For bike route signs to be functional, supplemental plaques can be placed beneath them when located along routes leading to high demand destinations (e.g. “To Downtown,” “To Transit Center,” etc.) Since bicycle route continuity is important, directional changes should be signed with appropriate arrow subplaques. Signing should not end at a barrier. Instead, information directing the cyclist around the barrier should be provided. According to the Manual on Uniform Traffic Control Devices (MUTCD), Part 2A-6: “Care should be taken not to install too many signs. A conservative use of regulatory and warning signs is recommended as these signs, if used to excess, tend to lose their effectiveness. On the other hand, a frequent display of route markers and directional signs to keep the driver informed of his location and his course will not lessen their value.” “BIKE ROUTE” -This sign is intended for use where no unique designation of routes is desired. However, when used alone, this sign conveys very little information. It can be used in connection with supplemental destination and distance plaques. (See Section 1003-3 of the Caltrans Highway Design Manual and Part 9B-22 of the MUTCD for specific information on subplaque options.) Facility Guidelines City of Temecula Page 9-16 Chapter 9 Roadways that are appropriate for bicycle use, but are undesignated, usually do not require regulatory, guide or informational signing in excess of what is normally required for motorists. In certain situations, however, additional signing may be needed to advise both motorists and cyclists of the shared use of the roadway, including the travel lane. “NO PARKING/BIKE LANE” -This is a combination sign used by the City of Carlsbad where designation of a route is needed, but where the prevention of automobile parking within the bicycle lane is also a priority. The City of Carlsbad uses it on roadways in beach areas where parking pressures are the greatest. In the City of Temecula it may be useful around schools where parents dropping off students can block bike routes leading to the schools. “SHARE THE ROAD” -Though not currently used by the City of Temecula, this sign is recommended where the following roadway conditions occur: • Shared lanes (especially if lane widths do not comply with Table 9-1) with relatively high posted travel speeds of 40 mph or greater; • Shared lanes (conforming with Table 9-1) in areas of limited sight distance; • Situations where shared lanes or demarcated shoulders or marked bike lanes are dropped or end and bicycle and motor vehicle traffic must begin to share the travel lane; • Steep descending grades where bicycle traffic may be operating at higher speeds and requires additional maneuvering room to shy away from pavement edge conditions; • Steep ascending grades, especially where there is no paved shoulder, or the shared lane is not adequately wide and bicycle traffic may require additional maneuvering room to maintain balance at slow operating speeds; • High volume urban conditions, especially those with travel lanes less than the recommended width for lane sharing; • Other situations where it is determined to be advisable to alert motorists of the likely presence of bicycle traffic and to alert all traffic of the need to share available roadway space. 9.3.13 Intersections and Driveways High speed, wide radius intersection designs increase traffic throughput for motor vehicles by minimizing speed differentials between entering and exiting vehicles and through vehicles. However, these designs exacerbate speed differential problems faced by cyclists traveling along the right side of a roadway and encourage drivers to fail to yield the right-of-way to cyclists. As a result, where wide radius turns are being considered, specific measures should be employed to ensure that the movement of cyclists along the roadway will be visible to motorists and to provide cyclists with a safe area to operate to the left of these wide radius right turn lanes. One method to accomplish this is to stripe (dash) a bicycle lane throughout the intersection area. Also, “SHARE THE ROAD” signs should be posted in advance of the intersection to alert existing traffic. In general, however, curb radii should be limited to distances which communicate to the motorist that he or she must yield the right-of-way to cyclists traveling along the roadway, or to pedestrians walking along the sidewalk or roadway margin. Sand, gravel and other debris in the cyclist’s path present potential hazards. In order to minimize the possibility of debris from being drawn onto the pavement surface from unpaved intersecting streets and driveways, during new construction, reconstruction and resurfacing, all unimproved intersecting streets and driveways should be paved back to the right-of-way line or a distance of 10 feet. Where curb cuts permit access to roadways from abutting unpaved parking lots, a paved apron should be paved back to the right-of-way line, preferably 10 feet from the curb line. These Chapter 9 Page 9-17 Multi-Use Trails and Bikeways Master Plan practices will lessen the need for maintenance debris removal. The placement of the paved back area or apron should be the responsibility of those requesting permits for access via curb cuts from driveways and parking lots onto the roadway system. 9.3.14 Roadside Obstacles To make certain that as much of the paved surface as possible is usable by bicycle traffic, obstructions such as sign posts, light standards, utility poles and other similar appurtenances should be set back a one foot minimum “shy distance” from the curb or pavement edge with exceptions for guard rail placement in certain instances. Additional separation distance to lateral obstructions is desirable. Where there is currently insufficient width of paved surface to accommodate bicycle traffic, any placement of equipment should be set back far enough to allow room for future projects (i.e. widening, resurfacing) to bring the pavement width into conformance with these guidelines. Vertical clearance to obstructions should be a minimum of eight and half feet. (See Section 1003.1 of the Caltrans Highway Design Manual.) 9.3.15 TSM Type Improvements Transportation Systems Management (TSM) improvements are minor roadway improvements which enhance motor vehicle flow and capacity. They include intersection improvements, channelization, the addition of auxiliary lanes, turning lanes and climbing lanes. TSM improvements must consider the needs of bicycle traffic in their design, or they may seriously degrade the ability of the roadway to safely accommodate cyclists. The inclusion of wider travel lanes or adjacent bike lanes will decrease traffic conflicts and increase vehicular flow. Designs should provide for bicycle compatible lanes or paved shoulders. Generally, this requires that the outside through lane and (if provided) turning lane be 14 feet wide. Auxiliary or climbing lanes should conform with Table 9-1 by either providing an adjacent paved shoulder, or a shared lane width of at least 15 feet. Where shared lanes and shoulders are not provided, it must be assumed that bicycle traffic will take the lane. 9.3.16 Marginal Improvements/Retrofitting Existing Roadways There may be instances or locations where it is not feasible to fully implement guidelines pertaining to the provision of adequate pavement space for shared use due to environmental constraints or unavoidable obstacles. In such cases, warning signs and/or pavement striping must be employed to alert cyclists and motorists of the obstruction, alert motorists and cyclist of the need to share available pavement space, identify alternate routes (if they exist), or otherwise mitigate the obstruction. On stretches of roadway where it is not possible to provide recommended shoulder or lane widths to accommodate shared use, conditions for bicycle traffic can be improved by: • Striping wider outside lanes and narrower interior lanes • Providing a limited paved shoulder area by striping a narrow travel lane. This tends to slow motor vehicle operating speeds and establish a space (with attendant psychological benefits) for bicycle operation Where narrow bridges create a constriction, “zebra“ striping should be used to shift traffic away from the parapet and provide space for bicycle traffic Other possible strategies include: • Elimination of parking or restricting it to one side of the roadway Facility Guidelines City of Temecula Page 9-18 Chapter 9 • Reduction of travel lanes from two in each direction to one in each direction plus center turn lane and shoulders • Reduction of the number of travel lanes in each direction and the inclusion or establishment of paved shoulders 9.3.17 Access Control Frequent access driveways, especially commercial access driveways, tend to convert the right lane of a roadway and its shoulder area into an extended auxiliary acceleration and deceleration lane. Frequent turning movements, merging movements and vehicle occupancy of the shoulder can severely limit the ability of cyclists to utilize the roadway and are the primary causes of motor vehicle-bicycle collisions. As a result, access control measures should be employed to minimize the number of entrances and exits onto roadways. For driveways having a wide curb radius, consideration should be given to marking a bicycle lane through the driveway intersection areas. As with other types of street intersections, driveways should be designed with sufficiently tight curb radii to clearly communicate to motorists that they must fully stop and then yield the right-of-way to cyclists and pedestrians on the roadway. 9.3.18 Bikeway Reconstruction after Construction Since roadways with designated bicycle facilities carry the largest volumes of users, their reconstruction should be of particular concern. Unfortunately, bicycle facilities are often installed piecemeal and users can find themselves facing construction detours and poor integration of facilities where the facilities begin and end. Bicycles facilities also sometimes seem to “disappear” after roadway construction occurs. This can happen incrementally as paving repairs are made over time and are not followed by proper bikeway restriping. When combined with poor surface reconstruction following long periods out of service due to road work, this can result in the eventual loss of affected bikeway facilities and decrease the number of cyclists regularly using bicycle facilities within the City of Temecula. Adjacent construction projects that require the demolition and rebuilding of roadway surfaces can cause problems in maintaining and restoring bikeway function. Construction activities controlled through the issuance of permits, especially driveway, drainage, utility, or street opening permits, can have an important effect on the quality of a roadway surface where cyclists operate. Such construction can create hazards such as mismatched pavement heights, rough surfaces or longitudinal gaps in adjoining pavements, or other pavement irregularities. Permit conditions should ensure that pavement foundation and surface treatments are restored to their preconstruction conditions, that no vertical irregularities will result and that no longitudinal cracks will develop. Stricter specifications, standards and inspections designed to prevent these problems should be developed, as well as more effective control of construction activities wherever bikeways must be temporarily demolished. A five year bond should be held to assure correction of any deterioration which might occur as a result of faulty reconstruction of the roadway surface. Spot widening associated with new access driveways frequently results in the relocation of drainage grates. Any such relocation should be designed to close permanently the old drainage structure and restore the roadway surface. New drainage structures should be selected and located to comply with drainage provisions established in these guidelines. Chapter 9 Page 9-19 Multi-Use Trails and Bikeways Master Plan 9.3.19 Maintenance Priorities Bikeway maintenance is easily overlooked. The “sweeping” effect of passing motor vehicle traffic readily pushes debris toward the roadway edges where it can accumulate within an adjoining bicycle facility. Litter and broken glass usually ends up in these areas as well. Since the potential for loss of control can exist due to a blowout caused by broken glass, or through swerving to avoid other debris, proper maintenance is directly related to safety. For this reason, street sweeping must be a priority on roadways with bike facilities, especially in the curb lanes and along the curbs themselves. The police department could assist by requiring towing companies to fully clean up accident scene debris, or face a fine. This would prevent glass and debris from being left in place after a motor vehicle accident, or simply swept into the curb or shoulder area. Suggested minimum sweeping schedule: • Class 1: heavy use monthly light use twice/year • Class 2: heavy use monthly • Class 3: twice/year The availability of a forum through which citizens can conveniently notify the proper city authority of bicycle facility problems or shortcomings is desirable. The City of San Diego Street Division, for example, makes available a Service Request form via the city’s Internet home page to allow citizens to report problems relating to streets, sidewalks, drains and other civil engineering infrastructural issues. It does not specifically mention bicycle facilities in its list of selected problems, but does offer the user the opportunity to type in the particulars of any street-related issue. 9.3.20 Intermodal Planning and Facilities Creating an environment conducive to intermodal transit begins with providing desirable facilities and amenities in locations convenient enough to attract potential users. Such facilities can include those described in the following sections. • Bike Lockers and Racks The provision of bicycle racks and lockers is an important first step in making a multi-modal system work for cyclists. Their presence encourages cyclists to use available transit because these facilities help to alleviate concerns about security, primarily theft or vandalism of bicycles parked for long periods. • Additional Bus-mounted Racks The provision of bus-mounted bicycle racks on more bus routes may encourage cyclists to use the bus system, especially in the outlying sections of the city where topography is the most pronounced. These racks should be mounted on the front of the bus to increase visibility between the bus driver and the cyclist using the rack and to decrease the chance of theft while the bus is stopped. 9.3.21 Traffic Calming There exist roadway conditions in practically all communities where controlling traffic movements and reducing motor vehicle speeds is a worthwhile way to create a safer and less stressful environment for the benefit of non-motorized users such as pedestrians and cyclists. These controlling measures are referred to as traffic calming. These measures are also intended to mitigate impacts of vehicular traffic such as noise, accidents and air pollution, but the primary link between traffic calming and bicycle planning is the relationship between motor vehicle speed and the severity of accidents. European studies have shown that instituting traffic calming techniques significantly decreases the number of pedestrian and cyclist fatalities in accidents involving motor vehicles, as well as the level of injuries and air pollution, without decreasing traffic volume. Facility Guidelines City of Temecula Page 9-20 Chapter 9 • Stop Signs/Yield Signs The installation of stop signs is a common traffic calming device intended to discourage vehicular through traffic by making the route slower for motorists. However, stop signs are not speed control devices, but rather right-of-way control devices. They do not slow the moving speed of motor vehicles and compliance by cyclists is very low. Requiring motor vehicles to stop excessively also contributes to air pollution. Cyclists are even more inconvenienced by stop signs than motorists because unnecessary stopping requires them to repeatedly reestablish forward momentum. The use of stop signs as a traffic management tool is not generally recommended unless a bicycle route must intersect streets with high motor vehicle traffic volumes. Controlled intersections generally facilitate bicycle use and improve safety and stop signs tend to facilitate bicycle movement across streets with heavy motor vehicular traffic. An alternative to stop signs may be to use yield signs or other traffic calming devices as methods to increase motorist awareness of crossing cyclists. • Speed Bumps and Tables Though many cities no longer install speed bumps, they have been shown to slow motor vehicle traffic speeds and reduce volume. If speed bumps are employed as a traffic management tool, a sufficiently wide gap must be provided to allow unimpeded bicycle travel around the bump to prevent safety hazards for cyclists. Standard advance warning signs and markers must be installed as well. • Partial Traffic Diverters These traffic calming devices include traffic circles and chicanes, both of which force traffic to follow a curved path which had formerly been straight. They are usually employed in areas of traditional grid street configuration. These devices can actually increase traffic hazards if they are not substantial enough to decrease motor vehicle speeds, or if appropriate side street access points are not controlled. • Total Traffic Diverters These diverters close roadways to motor vehicles only, or divert them to other routes while continuing to provide access to non-motorized users. Partial diverters allow access for cyclists in both directions, but block motor vehicle entry at one end. Both devices reduce motor vehicle driver options as a means to reduce the local traffic volume while allowing unrestricted access for pedestrians and cyclists. They are only useful where bicycles are fully exempt from the restrictions preventing the access of motor vehicles. Bicycle access should be clearly signed where motor vehicle access is limited so that cyclists are made aware that they can proceed even though motor vehicles can not. • Curb Extensions and Radius Reductions Larger curb radii are intended to facilitate high speed right-turn movements for the convenience of motorists. However, these larger radii are more dangerous for crossing and adjacent cyclists and pedestrians both because of the resulting higher motor vehicle speeds and the longer crossing distance for the cyclists and pedestrians. Motorists tend to spend less time looking for pedestrians and cyclists when they are attempting to make a high speed turn because their attention is focused on watching for oncoming traffic from the left. Their tendency to watch for pedestrians crossing from the right is also reduced. In addition, this type of intersection encourages higher speed movements across the bicycle travel lane, increasing the risk of collisions. To avoid these problems, curb radii should be reduced and curb extensions installed that pinch in toward the motor vehicle traffic lanes. This narrowing of the roadway tends to reduce traffic speeds, which creates a longer period for drivers to see potential conflicts before making right turns. However, due to the resulting reductions in motor vehicle speeds, this approach may not be appropriate at congested intersections. In such cases, there should instead be a safe lane and crossover segment especially for cyclists. Chapter 9 Page 9-21 Multi-Use Trails and Bikeways Master Plan Extensions are curb bulbs extending into the intersection from the corners of one or both of the intersecting roadways. Reducing curb radii functionally narrows the intersection, shortening the crossing distance for pedestrians and cyclists and slowing approaching traffic. Curb extensions are even more effective than reduced curb radii in decreasing crossing distance and slowing traffic. They can also serve the additional purposes of defining parking lanes and improving visibility at corners. The use of curb extensions should be confined to residential areas with limited through traffic since they limit the use of the curb lane to parking instead of providing extra roadway space beneficial for cycling. Reduced curb radii can be used more widely, but should not be used on streets with bus service, or on streets with routine large truck use requiring right turns. • Street Trees Street trees not only improve the immediate environment for all users, they also decrease the perceptual scale of the street. This tends to cause motor vehicle traffic to slow down. 9.4 Class 1 Multi-Use Trail Guidelines Class 1 facilities are generally paved multi-use paths or trails, separated from motor vehicle traffic. Off street routes are rarely constructed for the exclusive use of cyclists since other non-motorized user types will also find such facilities attractive. For that reason, the facilities recommended in this master plan should be considered multi-use where cyclists will share the pathways with other users. The recommended Class 1 routes (bike paths) are primarily intended to provide commuting routes through areas that are not yet served by roadways. Their primary purpose notwithstanding, most cyclists will find bicycle paths inviting routes to ride, especially if travel efficiency is secondary to enjoyment of cycling. Since these paths would augment the existing roadway system, they can extend circulation options for cyclists, making trips feasible which would would not otherwise be possible if the cyclists had to depend exclusively on roadways, especially in areas where usable roads are limited. Class B and C (casual and children) cyclists would likely also appreciate the relative freedom from conflicts with motor vehicles compared to riding on typical roadways. The presence of a Class 1 route near an existing roadway should not be construed as justification for prohibiting bicycles on the parallel or nearly parallel roadway. In some cases, this master plan calls for Class 1 routes parallel to the alignments of planned or existing roadways. According to the City transportation element, most new roadways are planned to include Class 2 bike lanes. Parallel facilities should be retained because experienced cyclists may find Class 1 paths inappropriate because of intensive use, or the routes may not be direct enough to suit the experienced cyclist. By the same token, the Class 1 path will likely be much more attractive to less experienced cyclists than a parallel facility on the street. In general, Class 1 facilities should not be placed immediately adjacent to roadways. Where such conditions exist, Class 1 facilities should be offset from the street as much as possible and separated from it by a physical barrier. These measures are intended to promote safety for both the cyclists and the motorists by preventing movement between the street and the Class 1 facility. 9.4.1 Class 1 Planning Issues • Shared Use of Multiple Use Path Since off-street paths (Class 1) are now rarely constructed for the exclusive use of cyclists, they must be designed for the safety of cyclists and other expected user types. Heavy use of multiuse trails can create conflicts between different types of users. These conflicts can include speed differentials between inexperienced and experienced cyclists as well as between Facility Guidelines City of Temecula Page 9-22 Chapter 9 pedestrians, joggers and in-line skaters, differences in the movements typical of particular user types and even the kinds of groupings common to the different user types as they casually move down the pathway. As long as volumes are low, the level of conflict between different user types can be managed without enforcement. However, even moderate increases in user volume can create substantial deterioration in level of service and safety. Conflicts between different user types are especially likely to occur on regionally significant recreational trails that attract a broad diversity of users, especially adjacent to the creeks. In general, paths that are expected to receive heavy use should be a minimum of 14 feet wide, paths expected to experience moderate use should be at least 12 feet wide and low volume paths can be 10 feet wide. Caltrans Class 1 requirements call for eight feet (2.4 meters) as the minimum width with two foot (0.6 meters) clear areas on each side. • Regulation of Multiple Use Paths The potential for multiple-use path conflicts has increased substantially in recent years with the increased popularity of jogging, mountain bikes and in-line skating. Where multi-use trails were once commonly used primarily by pedestrians and secondarily by cyclists, today they tend to be used by a roughly equal distribution of pedestrians, cyclists and in-line skaters. In-line skating has been the fastest growing sport in America for several years. Also, the majority of bicycles sold in the United States over the last decade have been mountain bikes, far outstripping sales of typical road bikes. The mountain bike’s relative comfort and upright riding position have helped to encourage inexperienced cyclists who previously rarely rode to do so more often. Methods used to reduce trail conflicts have included providing separate facilities for different groups, prohibiting certain user types, restricting certain uses to specific hours, widening existing facilities or marking lanes to regulate traffic flow. Examples of all of these types of actions occur along the coastal trails of southern California where conflicts between different user types can be especially severe during peak periods. • Compatibility of Multiple Use of Paths or Trails Joint use of paths by cyclists and equestrians can pose problems due to the ease with which horses can be startled. Also, the requirements of a Class 1 bicycle facility include a solid surface, which is not desirable for horses. Therefore, where either equestrian or cycling activity is expected to be high, separate trails are recommended. On facilities where Class 1 designation is not needed and the facility will be unpaved, mountain bikes and horses can share the trail if adequate passing width is provided, the expected volume of traffic by both groups is low and available sight distances allow equestrians and cyclists to anticipate and prepare for possible conflicts. Education of all trail users in “trail etiquette” has proven to be helpful on shared trails elsewhere. The recent surge in the popularity of mountain bikes have increased conflicts on narrow trails with minimal surface improvements that were originally designed for hiking alone. On some trails, especially ones that are contiguous over distances greater than the average hiker’s typical one day hiking range, mountain bikes now commonly outnumber hikers. The primary problem with this mixed use is the speed differential between mountain bikers and hikers. This speed difference is exacerbated by additional concerns such as limited sight distances due to topography and vegetation. Mountain bikes can also cause some erosion or compaction problems. Therefore, mountain bike use should be restricted to wider multi-use trails and dirt roads that have adequate sight distances and drainage improvements to protect against erosion. Once again, education is an important component in minimizing conflicts. This includes situations where adjacent vegetation or habitat is considered sensitive. Signs restricting users to the trail may be Chapter 9 Page 9-23 Multi-Use Trails and Bikeways Master Plan sufficient, though the addition of fencing or railings may be required if signage does not achieve the desired results. • Urban Access Pathways Conflicts between different user types on multiple use routes occur primarily on heavily used recreational paths, or near major pedestrian trip generators. Lightly used neighborhood pathways and community trails can be safely shared by a variety of user types. Construction of urban access pathways between adjoining residential developments, schools, neighborhoods and surrounding streets can substantially expand the circulation opportunities for both pedestrians and cyclists. However, bicycle use of urban access pathways should not include sidewalks adjacent to streets for a number of reasons. First, sidewalks are designed for pedestrian speeds and maneuverability. Second, they are usually encumbered by parking meters, utility poles, benches, trees, etc. Third, other types of users and their specific types types of maneuverability can also pose a safety issue for cyclists. Though sidewalks are, in general, not conducive to safe cycling, an exception is Class C cyclists, young children. This type of bicycle use is generally acceptable because it provides young children who do not yet have the judgment or skill to ride in the street an opportunity to develop their riding skills. Sidewalks in residential areas generally have low pedestrian volumes and are usually accepted as play areas for children. Finally, one other exception to sidewalk use by cyclists should be allowed. This is where the walkway is at least eight feet wide and well away from streets, such as within parks. In such cases, bicycle use on walkways can occur safely. • Bicycle Paths Adjacent to Roadways Two-way bicycle facilities located immediately adjacent to a roadway are not generally recommended because they require one direction of bicycle traffic to ride against motor vehicle traffic, contrary to the normal “Rules of the Road.” This puts the wrong way cyclists in the motorists’ “blind spot” at intersections where they do not have the right-of-way, or are not noticed by motorists turning right because the cyclists are not on the roadway. Many cyclists will also find it less convenient to ride on this type of facility as compared to streets, especially for utility trips such as commuting. This more experienced group of cyclists may find the roadway more efficient, safer, or better maintained than the adjacent bicycle facility. The AASHTO guide says that: “...bicycle lanes, or shared roadways should generally be used to accommodate bicycle traffic along highway corridors rather than providing a bicycle path immediately adjacent to the highway.” An exception to this general rule can occur where an off-road route intended primarily for bicycle use must be located adjacent to a roadway for a short distance to maintain trail continuity such as when an existing roadway’s bridge will be used by the trail. Even so, physical separation of the bicycle facility from the roadway must be provided. 9.5 Design of Class 1 Facilities (Paved Paths Primarily Used by Bicycles) Wherever possible, paved off-street trails should follow Caltrans Class 1 guidelines for two very important reasons. The first is safety. Wheeled users on a paved trail can attain fairly high speeds. Caltran’s width and sight distance requirements, for example, helps to prevent collisions by providing maneuvering space and shy distance. The second consideration is funding. If a facility is not planned to comply with Caltrans guidelines, funding becomes much more limited. There is consid Facility Guidelines City of Temecula Page 9-24 Chapter 9 erably more bikeway funding available than there is for recreational trails. Also, if a municipality decides to build a paved trail narrower than Caltrans guidelines requires, the additional cost of building it to the Caltrans-mandated width is likely to be more than offset by funding that would then become available. Only where there is no requirement or desire for Caltrans-administered funds, or where Class 1 type improvements are simply undesirable, or where trail use will be very light can physical requirements be relaxed for paved trails. In some cases, specific site restrictions may require the paved trail design to fall outside of Caltrans guidelines. Where that does occur, every effort should be made to make the situation as safe as possible and to alert users to any potential hazards. The guidelines in Section 9.3.14, Unavoidable Obstacles, should be followed as closely as possible. A substantial portion of the following sections are taken directly from the 1991 AASHTO Guide for the Development of Bicycle Facilities. In keeping with standards employed in other reviewed master plans, the AASHTO excerpts are italicized. Note that AASHTO’s use of the term “bicycle path” is equivalent to a “Class 1 bicycle facility” as defined by Caltrans and as used in this master plan. Also, the AASHTO term “highway” is synonymous with the term “roadway.” Finally, all measurements in the Caltrans documents are now in metric form. 9.5.1 Width and Clearance The paved width and the operating width required for a bicycle path are primary design considerations. Under most conditions, recommended paved width for a two-directional bicycle path is 10 feet. In some instances, however, a minimum of eight feet can be adequate. This minimum should be used only where the following conditions prevail: (1) bicycle traffic is expected to be low, even on peak days or during peak hours; (2) pedestrian use of the facility is not expected to be more than occasional; (3) there will be be good horizontal and vertical alignment providing safe and frequent passing opportunities; and (4) the path will not be subject to maintenance vehicle loading conditions that would cause pavement edge damage. Under certain conditions it may be necessary or desirable to increase the width of bicycle path to 12 feet or more, for example, because of substantial bicycle volume, probable shared use with joggers and other pedestrians, use by large maintenance vehicles, steep grades, or where bicycles will be likely to ride two abreast. Reduced widths are acceptable on access pathways due to their generally short length and low volumes. However, wherever possible, minimum width standards should be employed. One-directional bicycle facilities are not generally recommended since they will almost certainly be used as two-way facilities. A minimum of two feet width graded area should be maintained adjacent to both sides of the pavement. However, three feet or more is desirable to provide clearance from trees, poles, poles, walls, fences, guardrails, or other lateral guidelines. A wider graded area on either side of the bicycle path can serve as a separate jogging path. The vertical clearance to obstructions should be a minimum of eight feet. However, vertical clearance may need to be greater to permit passage of maintenance vehicles and, in undercrossings and tunnels, a clearance of 10 feet is desirable for adequate vertical shy distance. 9.5.2 Horizontal Separation from Roadways Class 1 bicycle facilities are generally physically separated from roadways. However, where a Class 1 facility must be considered within a roadway right-of-way, a wide separation between a bicycle path and adjacent highway is desirable to confirm for both the cyclist and the motorist that the bicycle path functions as an independent highway for bicycle traffic. In addition to physical separation, landscaping or other visual buffer is desirable. When this is not possible and the distance between the edge of the roadway and the bicycle path is less than five feet, a suitable physical divider may be considered. Such dividers serve both Chapter 9 Page 9-25 Multi-Use Trails and Bikeways Master Plan to prevent cyclists from making unwanted movements between the path and the highway shoulder for the protection of cyclists from motor vehicles and to reinforce the concept that the bicycle path is an independent facility. Where used, the divider should be a minimum of 4.5 feet high, to prevent cyclists from toppling over it and it should be designed so that it does not become an obstruction or traffic hazard in itself. 9.5.3 Design Speed The speed that a cyclist travels is dependent on several factors, including the type and condition of the bicycle, the purpose of the trip, the condition and location of the bicycle path, the speed and direction of the wind and the physical condition of the cyclist. Bicycle paths should be designed for a selected speed that is at least as high as the preferred speed of the faster cyclists. In general, a minimum design speed of 20 mph should be used. However, when the grade exceeds four percent, a design speed of of 30 mph is advisable. 9.5.4 Horizontal Alignment and Superelevation The minimum radius of curvature negotiable by a bicycle is a function of the superelevation rate of the bicycle path surface, the coefficient of friction between the bicycle tires and the bicycle path surface and the speed of the bicycle. The minimum design radius of curvature can be derived from the following formula: R = Minimum radius of curvature (meters) V= Design speed (kph) e = Rate of superelevation f = Coefficient of friction For most bicycle path applications, the superelevation rate will vary from a minimum two percent (the minimum necessary to encourage adequate drainage) to a maximum of approximately five percent (beyond which maneuvering difficulties by slow bicycles and adult tricyclists might be expected). The minimum superelevation rate of two percent will be adequate for most conditions and will simplify construction. The coefficient of friction depends upon speed; surface type, roughness and condition; tire type and condition; and whether the surface is wet or dry. Friction factors used for design should be selected based upon the point at which centrifugal force causes the cyclist to recognize a feeling of discomfort and instinctively act to avoid higher speed. Extrapolating from values used in highway design, design factors for paved bicycle paths can be assumed to vary from 0.30 at 15 mph to 0.22 at 30 mph. (Based on a superelevation rate (e) of two percent, minimum radii of curvature can be selected from Figure 1003.1C of the Caltrans Highway Design Manual.) When substandard radius curves must be used on bicycle paths because of right-of-way, topographical, or other considerations, standard curve warning signs and supplemental pavement markings should be installed in accordance with the Caltrans Highway Design Manual. The negative effects of substandard curves can also be partially offset by widening the pavement through the curves. 9.5.5 Grade Grades on bicycle paths should be kept to a minimum, especially on long inclines. Grades greater than five percent are undesirable because the ascents are difficult for many cyclists and the descents cause some cyclists to exceed the speeds at which they are competent. Where terrain dictates, grades over five percent and less than 500 feet long are acceptable when a higher design speed is used and additional width is provided. 127 +f R= V2 e ( 1 0 0 ) Facility Guidelines City of Temecula Page 9-26 Chapter 9 9.5.6 Switchbacks In areas of steep terrain, a series of “switchbacks” may be the only solution to traversing changes in elevation. At these locations, a grade of eight percent is acceptable for a distance of no more than 100 feet. Grades steeper than eight percent will not meet Americans with Disabilities Act (ADA) standards. Switchback radii should be larger than normally employed for pedestrian facilities to allow for cyclists to be able to safely make the turns without having to dismount. Pavement width should be a minimum of 12 feet wide to allow ascending cyclists room to walk their bicycles when necessary. The switchbacks should be completely visible from the next uphill turn. Runouts at the end of each turn should be considered for cyclists unable to slow down quickly enough to make the turn. Railings should be installed to discourage shortcuts and appropriate signing should be placed at the top of the descent. 9.5.7 Sight Distances To provide provide cyclists with an opportunity to see and react to the unexpected, a bicycle path should be designed with adequate stopping sight distance. The distance required to bring a bicycle to a full controlled stop is a function of the cyclist’s perception and brake reaction time, the initial speed of the bicycle, the coefficient of friction between the tires and the pavement and the braking ability of the bicycle. Figure 1003.1D of the Caltrans Highway Design Manual indicates the minimum stopping sight distance for various design speeds and grades based on a coefficient of 0.25 to account for the poor wet weather braking characteristics of many bicycles. For two-way bicycle paths, the sight distance in descending direction, that is, where “G” is negative, will control the design. 9.5.8 Intersections Intersections with roadways are important considerations in bicycle path design. If alternate locations for a bicycle path are available, the one with the most favorable intersection conditions should be selected. For crossings of freeways and other high-speed, high-volume arterials, a grade separation structure may be the only possible or practical treatment. Unless bicycles are prohibited from the crossing highway, providing for turning movements must be considered. When intersections occur at grade, a major consideration is the establishment of right-of-way. The type of traffic control to be used (signal, stop sign, yield sign, etc.) and locations, should be provided in accordance with the Caltrans Traffic Manual. Sign type, size and location should also be in accordance with the Caltrans Traffic Manual. Care should be taken to ensure that bicycle path signs are located so that motorists are not confused by them and that roadway signs are placed so that cyclists are not confused by them. Other means of alerting cyclists of a highway crossing include grade changes or changing surfaces at the approach. Devices installed to prohibit motorists from entering the bike path can also assist with alerting cyclists to crossings. It is preferable that the crossing of a bicycle path and a highway be at a location away from the influence of intersections with other highways. Controlling vehicle movements at such intersections is more easily and safely accomplished through the application of standard traffic control devices and normal Rules of the Road. Where physical constraints prohibit such independent intersections, the crossings may be at or adjacent to the pedestrian crossing. Right-of-way should be assigned and sight distance should be provided so as to minimize the potential for conflict resulting from unconventional turning movements. At crossings of high volume multi-lane arterial highways where signals are not warranted, consideration should be given to providing a median refuge area for cyclists. Chapter 9 Page 9-27 Multi-Use Trails and Bikeways Master Plan When bicycle paths terminate at existing roads, it is important to integrate the path into the existing system of roadways. Care should be taken to properly design the terminals to transition the traffic into a safe merging or diverging situation. Appropriate signing is necessary to warn and direct both cyclists and motorists regarding these transition areas. Bicycle path intersections and approaches should be on relatively flat grades. Stopping sight distances at intersections should be checked and adequate warning should be given to permit cyclists to stop before reaching the intersection, especially on downgrades. Ramps for curb cuts at intersections should be the same width as the bicycle paths. Curb cuts and ramps should provide a smooth transition between the bicycle paths and the roadway. 9.5.9 Signing and Marking Adequate signing and marking are essential on bicycle paths, especially to alert cyclists to potential conflicts and to convey regulatory messages to both cyclists and motorists at highway intersections. In addition, guide signing, such as to indicate directions, destinations, distance, route numbers and names of crossing streets, should be used in the same manner as they are used on highways. In general, uniform application of traffic control devices, as described in the Caltrans Highway Design and Traffic Manuals, will tend to encourage proper cyclist behavior. A four inch wide yellow centerline stripe to separate opposite directions of travel should be considered. This is particularly beneficial in the following circumstances: (1) for heavy volumes of bicycles; (2) on curves with restricted sight distances; and (3) on unlighted paths where nighttime riding is expected. Edge lines can also be very beneficial where significant nighttime bicycle traffic is expected. General guidance on signing and marking is provided in the Caltrans Highway Design Manual. Care should be exercised in the choice of pavement marking materials. Some marking materials are slippery when wet and should be avoided in favor of more skid-resistant materials. 9.5.10 Pavement Structure Under most circumstances, a two inch thick asphalt top course placed on a six inch thick base is suitable for a bikeway pavement structure. Where unsatisfactory soils can be anticipated, a soil investigation should be conducted to determine the load-carrying capabilities of the native soil and the need for any special provisions. In addition, some basic differences between the operating characteristics of bicycles and those of motor vehicles should be recognized. While loads on bicycle paths will be substantially less than typical roadway loads, paths should be designed to sustain without damage the wheel loads of occasional emergency, patrol, maintenance and other motor vehicles that are expected to use or cross the path. Where such motor vehicle use will be required, four inches of asphalt should be used. Additional pavement structure may also be necessary in flood plains and in locations where shallow root systems may heave thin pavement sections. Special consideration should be given to the location of motor vehicle wheel loads on the path. When motor vehicles are driven on bicycle paths, their wheels will usually be at or very near the edges of the path. Since this can cause edge damage that, in turn, will result in the lowering of the effective operating width of the path, adequate edge support should be provided. Edge support can be either in the form of stabilized shoulders or in constructing additional pavement width. Constructing a typical pavement width of 12 feet, where right-of-way and other conditions permit, eliminates the edge raveling problem and offers Facility Guidelines City of Temecula Page 9-28 Chapter 9 two other additional advantages over shoulder construction. First, it allows additional maneuvering space for cyclists and second, the additional construction cost can be less than that for constructing shoulders because the separate construction operation is eliminated. It is important to construct and maintain a smooth riding surface on bicycle paths. Bicycle path pavements should be machine laid. Root barriers should be used where necessary to prevent vegetation from erupting through the pavement, and on Portland cement concrete pavements, transverse joints, necessary to control cracking, should be saw cut to provide a smooth ride. On the other hand, skid resistance qualities should not be sacrificed for the sake of smoothness. Broom finish or burlap drag concrete surfaces are preferred over trowel finishes, for example. At unpaved highway or driveway crossings of bicycle paths, the highway or driveway should be paved a minimum of 10 feet on each side of the crossing to reduce the amount of gravel being scattered along the path by motor vehicles. The pavement structure at the crossing should be adequate to sustain the expected loading at the location. 9.5.11 Structures An overpass, underpass, small bridge or drainage facility on a highway bridge may be necessary to provide continuity to a bicycle path. On new structures, the minimum clear width should be the same as the approaching paved bicycle path and the desirable clear width should include the minimum two foot wide clear areas. Carrying the clear areas across the structures has two advantages. First, it provides a minimum horizontal shy distance from the railing or barrier, and second, it provides needed maneuvering space to avoid conflicts with pedestrians and other cyclists who are stopped on the bridge. Access by emergency, patrol and maintenance vehicles should be considered in establishing the design clearances of structures on bicycle paths. Similarly, vertical clearance may be dictated by occasional motor vehicles using the path. Where practical, a vertical clearance of 10 feet is desirable for adequate vertical shy distance. Railings, fences, or barriers on both sides of a bicycle path structure should be a minimum of 4.5 feet high. Smooth rub rails should be attached to the barriers at handlebar height of 3.5 feet. Bridges designed exclusively for bicycle traffic may be designed for pedestrian live loading. On all bridge decks, special care should be taken to ensure that bicycle-safe expansion joints are used. Where it is necessary to retrofit a bicycle path onto an existing highway bridge, several alternatives should be considered in light of what the geometrics of the bridge will allow. One option is to carry the bicycle path across the bridge on one side. This should be done where (1) the bridge facility will connect to a bicycle path at both ends; (2) sufficient width exists on that side of the bridge, or can be obtained by widening or restriping lanes; and (3) provisions are made to physically separate bicycle traffic from motor vehicle traffic as discussed above. A second option is to provide either wide curb lanes or bicycle lanes over the bridge. This may be advisable where (1) the bicycle path transitions into bicycle lanes at one end of the bridge; and (2) sufficient width exists, or can be obtained by widening or restriping. A third option is to use existing sidewalks as oneway or two-way facilities. This may be advisable where (1) conflicts between cyclists and pedestrians will not exceed tolerable limits; and (2) the existing sidewalks are adequately wide. Under certain conditions, the cyclist may be required to dismount and cross the structure as a pedestrian. Because of the large number of variables involved in retrofitting bicycle facilities onto existing bridges, compromises in desirable design criteria are often inevitable. Therefore, the width to be Chapter 9 Page 9-29 Multi-Use Trails and Bikeways Master Plan provided is best determined by the designer, on a case-by-case basis, after thoroughly considering all the variables. 9.5.12 Drainage The recommended minimum pavement cross slope of two percent adequately provides for drainage. Sloping in one direction instead of crowning is preferred and usually simplifies the drainage and surface construction. A smooth surface is essential to prevent water ponding and ice formation, where this can occur. Where a bicycle path is constructed on the side of a hill, a ditch of suitable dimensions should be placed on the uphill side to intercept the hillside drainage. Such ditches should be designed in such a way that no undue obstacles are presented to cyclists. Where necessary, catch basins with drains should be provided to carry the intercepted water under the path. Drainage grates and manhole covers should be located outside of the travel path of the cyclist. (See Section 1003.6 of the Caltrans Highway Design Manual.) To assist in draining the area adjacent to the bicycle path, the design should include considerations for preserving the natural ground cover. Seeding, mulching and sodding of adjacent slopes, swales and other erodible areas should be included in the design plans. 9.5.13 Lighting Fixed-source lighting reduces conflicts along the paths and at intersections. In addition, lighting allows the cyclist to see the bicycle path direction, surface conditions and obstacles. Lighting for bicycle paths is important and should be considered where riding at night is expected, such as bicycle paths serving college students or commuters and at highway intersections. Lighting should also be considered through underpasses or tunnels and when nighttime security could be a problem. Depending on the location, average maintained horizontal illumination levels of 5 to 22 lux should be considered. Light standards (poles) should meet the recommended horizontal and vertical clearances. Luminaires and standards should be at a scale appropriate for a pedestrian or bicycle path. (See Section 1003.6 of the Caltrans Highway Design Manual.) 9.5.14 Barriers to Motor Vehicle Traffic Bicycle paths often need some type of physical barrier at highway intersections and pedestrianload bridges to prevent unauthorized motor vehicles from using the facilities. Provisions can be made for a lockable, removable post to permit entrance by authorized vehicles. The post should be permanently reflectorized for nighttime visibility and painted a bright color for improved daytime visibility. When more than one post is used, a five foot spacing is desirable. Wider spacing can allow entry to motor vehicles, while narrower spacing might prevent entry by adult tricycles and bicycles with trailers. Striping an envelope around the barrier is recommended. (See Section 1003.1 of the Caltrans Highway Design Manual.) An alternate method of restricting entry of motor vehicles is to split the entry way into two five foot sections separated by low landscaping. Emergency vehicles can still enter if necessary by straddling the landscape. The higher maintenance costs associated with landscaping should be acknowledged, however, before this alternative method is selected. 9.6 Design of Class 2 Facilities Class 2 facilities are marked bicycle lanes within roadways usually adjacent to the curb lane, delineated by appropriate striping and signage. Bicycle lanes can be considered when it is desirable to delineate available road space for preferential use by cyclists and motorists and to provide for more predictable movements by each. Bicycle lane markings can increase a cyclist’s confidence in motorists not straying into his/her path of travel. Likewise, passing motorists are less likely to swerve to the left out of their lane to avoid cyclists on their right. Facility Guidelines City of Temecula Page 9-30 Chapter 9 Bicycle lanes should always be one-way facilities and carry traffic in the same direction as adjacent motor vehicle traffic. Two-way bicycle lanes on one side of the roadway are unacceptable because they promote riding against the flow of motor vehicle traffic. Wrong-way riding is a major cause of bicycle accidents and violates the “Rules of the Road” stated in the Uniform Vehicle Code. Bicycle lanes on one-way streets should be on the right side of the street, except in areas where a bicycle lane on the left will decrease the number of conflicts (e.g., those caused by heavy bus traffic). In unique situations, it may be appropriate to provide a contra-flow bicycle lane on the left side of a one-way street. Where this occurs, the lane should be marked with a solid, double yellow line and the width of the lane should be increased by one foot. 9.6.1 Lane Widths Under ideal conditions, the minimum bicycle lane width is five feet. However, certain edge conditions dictate additional desirable bicycle lane width. Figure 1003.2A of the Caltrans Highway Design Manual depicts four common locations for such facilities in relation to the roadway. The first figure depicts bicycle lanes on an urban curbed street where a striped parking lane is provided. The minimum bicycle lane width for this location is five feet. If parking volume is substantial or turnover is high, an additional one or two feet of width is desirable for safe bicycle operation. Bicycle lanes should always be placed between the parking lane and the motor vehicle lanes. Bicycle lanes between the curb and the parking lane can create obstacles for cyclists and eliminate a cyclist’s ability to avoid a car door as it is opened. Therefore, this placement should not be considered. The second figure depicts an urban curbed street where parking is allowed, but without striping for a separate bike lane. This parking lane shared with bicycles should be 11 to 12 feet wide. 13 feet is recommended where parking turnover is high, such as commercial districts. Cyclists do not generally ride near a curb because of the possibility of debris, of hitting a pedal on the curb, of an uneven longitudinal joint, or of a steeper cross slope. The third figure shows a roadway where parking is prohibited. Bicycle lanes in this location should have a minimum width of five feet where a curb occurs (measured from the curb face) and four feet where no curb is used. If the longitudinal joint between the gutter pan and the roadway surface is uneven and falls within five feet of the curb face, a minimum of four feet should be provided between the joint and the motor vehicle lanes. The fourth figure depicts bicycle lanes on a roadway where parking is prohibited and without curbs. Bicycle lanes should be located between the motor vehicle lanes and the roadway shoulders. In this situation, bicycle lanes may have a minimum width of four feet, since the shoulder can provide additional maneuvering width. A width of five feet or greater is preferable. Additional widths are desirable where substantial truck traffic is present, or where vehicle speeds exceed 40 mph. In certain situations, it may be appropriate to designate the full shoulder as the bike lane. 9.6.2 Intersections Bicycle lanes tend to complicate both bicycle and motor vehicle turning movements at intersections. Because they encourage cyclists to keep to the right and motorists to keep to the left, both operators are somewhat discouraged from merging in advance of turns. Thus, some cyclists will begin left turns from the right side of the bicycle lane and some motorists will begin right turns from the left side of the bicycle lane. Both maneuvers are contrary to established Rules of the Road and result in conflicts. Design treatment for bicycle lanes at a simple intersection is shown in Figure 1003.2B of the Caltrans Highway Design Manual. On a two lane roadway, the edge line along the bike lane should Chapter 9 Page 9-31 Multi-Use Trails and Bikeways Master Plan end approximately 200 feet from the intersection to allow left turning cyclists and right turning motorists to “weave.” Design treatment at multi-lane intersections is more complex. Figure 1003.2C of the Caltrans Highway Design Manual presents examples of pavement markings for bicycle lanes approaching motorist right-turn-only lanes. Where there are numerous left turning cyclists, a separate turning lane should be considered. The design of bicycle lanes should also include appropriate signing at intersections to reduce the number of conflicts. General guidance for pavement marking of bicycle lanes is contained in Section 1003.2 of the Caltrans Highway Design Manual. (See the Caltrans Traffic Manual for more specific information.) Adequate pavement surface, bicycle-safe grate inlets and traffic signals responsive to bicycles should always be provided on roadways where bicycle lanes are being designated. Raised pavement markings and raised barriers barriers can cause steering difficulties for cyclists and should not be used to delineate bicycle lanes. 9.6.3 Signing and Striping Requirements Signing and striping should be in accordance with Section 1004 of the Caltrans Highway Design Manual and the Caltrans Traffic Manual. Bicycle lanes should be well-marked and signed to ensure clear understanding of the presence and purpose of the facility by both cyclists and motorists. The Caltrans Traffic Manual also specifies standard signing for bicycle lanes. The appropriate signs should be used in advance of the beginning of a marked designated bicycle lane to call attention to the lane and to the possible presence of cyclists. Signs should be used only in conjunction with the appropriate pavement marking and erected at periodic intervals along the designated bicycle lane and in the vicinity of locations where the preferential lane symbol is used. Where it is necessary to restrict parking, standing, or stopping in a designated bicycle lane, appropriate signs, as described in the Caltrans Traffic Manual, may be used. The City of Carlsbad, California, for example, also uses a combination “NO PARKING/BIKE LANE” sign where parking pressures are the greatest. Bicycle lane stripes should be solid, six to eight inch wide white lines. Care should be taken to use pavement striping that is skid-resistant. Thermoplastic tape and painted markings can become slippery and cause the cyclist to fall. Nonskid, preformed tape with impregnated grit is an acceptable striping material. It is very important to reapply bicycle lane markings when they begin to fade, since faded bicycle lane markings can lead to confusion for motorists and cyclists. If necessary, reapplication of bicycle lane stripes should be placed on a more frequent schedule than regular roadway restriping projects. Old markings should be removed prior to restriping if new layers of marking materials would otherwise create raised areas that would be hazardous to cyclists. Prompt replacement of bicycle lane striping following pavement repairs should be the responsibility of the paving contractor for projects that have required the removal and replacement of bike lane paving. Too often, lane striping is not replaced following construction or repaving projects. Preferential bicycle lane symbols should be installed on the pavement in bicycle lanes. Symbols should be installed at regular intervals (no more that 350 feet between symbols), immediately after intersections and at areas where bicycle lanes begin. Pavement letters that spell “BIKE ONLY,” and arrows are optional, but desirable. Facility Guidelines City of Temecula Page 9-32 Chapter 9 9.7 Design of Class 3 Facilities A Class 3 facility is a suggested bicycle route that usually consists of a series of signs designating a preferred route between destinations such as residential and shopping areas. A network of such routes can provide access to a number of destinations throughout the community. In some cases, looped systems of scenic routes have been created to provide users with a series of recreational experiences. In addition, such routes can provide relatively safe connections for commuting to workplaces or schools. The designation of a roadway as a Class 3 facility should be based primarily on the advisability of encouraging bicycle use on that particular roadway. While the roadways chosen for bicycle routes may not be free of problems, they should offer the best balance of safety and convenience of the available alternatives. In general, the most important considerations are pavement width and geometrics, traffic conditions and appropriateness of the intended purpose. A certain amount of risk and liability exists for any area that the City signs as a Class 3 route. The message to the user public is that the facility is a safe route. Therefore, routes should not be placed on streets that do not meet appropriate safety standards. Attributes which describe how appropriate a particular road is for a bicycle route include directness, connectivity with other bicycle facilities, scenery and available services. Directness is important for cyclists traveling for a purpose, such as commuting, though this is not the case for recreational riders, for whom scenery may be the primary factor in selecting a route. For recreational riders traveling more than a few miles, services such as food, water, restrooms and pressurized air may be of interest. 9.7.1 Roadway Engineering While design of all Class 1 and 2 bikeways should follow the Bikeway Planning and Design Chapter 1000 of the Caltrans Highway Design and Traffic Manuals, there are bound to be situations where the recommended geometrics for a Class 3 facility can not be achieved due to right-of-way constraints, for example. Planning and design of the Class 3 facility should emphasize safety for cyclists and provide additional warnings to motorists to be aware of the presence of cyclists.