Suburbs can be wonderful places for cycling. Recreational cyclists enjoy suburbs for their scenery and roads with fewer traffic signals to disrupt their pace. Utilitarian cyclists find that many suburban destinations that are beyond convenient walking distance or are not served by transit are easily reached by bike. However, the configuration and management of the transportation infrastructure can affect the comfort, convenience, and safety of cycling in suburbs. The following is a guide for transportation planners, engineers, and bicyclist advocates on how to improve suburbs for cycling.
Street Topology and Connectivity
Many of the first suburbs were built on a closely spaced grid of streets that provide a number of direct routes between destinations. This minimizes trip distances and allows the cyclist a choice of route type, including arterial and residential streets. New suburbs often feature a hierarchical road topology that requires the use of an arterial for every useful trip, and increases trip distances when entering and leaving residential subdivisions. This topology reduces the volume vehicle traffic in the subdivision, which is friendly to those who want to stay inside the subdivision, but it discourages utilitarian bicycle travel to non-residential destinations by adding several more minutes to every trip and requiring travel on high speed arterials that can be unpleasant for cycling.
Several approaches can be used to increase the convenience and comfort of suburban street networks for utilitarian cycling without sacrificing the quiet nature of suburban culs-de-sac. Arterial and collector through-streets may be spaced closer together (e.g. 1/2 mile apart instead of one mile or more) to reduce the trip distance to the edge of the neighborhood. Collector streets may be connected in series across arterial roads to provide longer, more useful low-speed routes. Neighborhood street connectivity may be increased to provide more convenient access to collectors. Residential collectors may be connected directly to commercial shopping centers and other everyday destinations to provide accessibility without requiring the use of a high speed arterial. Short-cut paths for non-motorized traffic can connect separate cul-de-sac networks together and provide children easier access to nearby schools and parks by reducing dependence on arterials. Trails alongside streams and on abandoned railway rights-of-way can provide pleasant recreational opportunities and sometimes support utilitarian use.
Suburban cyclists use all types of streets including neighborhood streets, downtown streets, old farm-to-market roads, and major arterials. All of these roads work well for cycling if they are built appropriately for the traffic that uses them.
Within residential neighborhoods, vehicle traffic volumes are generally low. There are often a significant amount of pedestrian traffic and vehicles parked in the street. Streets are generally short and sight lines may be limited. As a result, vehicle speeds are usually low and motorists are cautious. Where streets are narrow, cyclists can use an entire travel lane without creating significant delays for drivers of wider vehicles. Overtaking drivers have the option of using the adjacent lane to pass when safe, or waiting a short time until they reach a wider road.
Neighborhood collector roads typically carry higher volumes and speeds of vehicle traffic over longer distances than local access streets. Collectors may also serve as short-cuts through and between neighborhoods. (These short-cuts are especially useful to utilitarian cyclists, who are not as constrained by neighborhood-friendly speeds as are motorists, who usually prefer the faster travel speeds possible on arterials.) Collector roads that carry a mixture of automobile and bicycle traffic perform better when they are wide enough to allow easy overtaking of cyclists between intersections. A 16′ lane width accommodates 4′ to 5′ of maneuvering space for cyclists, 3′ to 4′ of passing distance, and 2′ of shy distance between vehicles and the opposite-direction traffic lane or a raised center median.
Arterial roads facilitate travel over long distances and provide priority over cross traffic. These roads accommodate faster travel speeds and carry high volumes of vehicle traffic at peak travel times. Arterials often provide cyclists the most efficient – and perhaps only – routes to their destinations. Roadway design that reduces friction between stopped, slow-moving, and faster traffic is desirable on most arterials outside of pedestrian-oriented downtown areas. Left-turn-lane pockets provide a safe place for cyclists to wait to turn left at intersections and commercial driveways. Wide (14′ or greater) outside through lanes allow easier passing of cyclists by car drivers on multi-lane roads without changing lanes; on two-lane roads, 16′ or wider lanes provide extra shy distance between opposite-direction traffic.
Suburban arterial roads often feature demand-actuated traffic signals. Cyclists are required by law to obey traffic signals; traffic signals that must sense vehicles to operate correctly must detect bicycles, especially at cross-streets and left-turn-lanes. This can be accomplished with properly designed and adjusted loop detectors or with video detection.
Many suburbs feature a compact downtown core built before automobile use became very popular. These areas often feature heavy pedestrian traffic and on-street parking. Traffic speeds should be low in these areas; often congestion lowers average motor vehicle speed to that of average bicycle speed. Cyclists face many more conflicts with opening car doors, pedestrians, and turning or crossing vehicles than with overtaking traffic. It is therefore important that any roadway designs intended to facilitate easier passing of cyclists not exacerbate the more acute safety problems for cyclists. Never stripe any part of a bicycle lane within four feet of parked cars. If travel lanes are too narrow for safe side-by-side sharing between cyclists and drivers of wide vehicles, education and enforcement should be used to make sure that everyone knows that cyclists are entitled to use an entire travel lane.
Rural roads that were designed to support low-traffic agricultural uses represent the majority of through roads outside the periphery of suburban areas. Many cyclists who enjoy the scenery and low traffic volumes of rural areas use these roads. Low-volume rural roads are often very narrow, requiring car drivers to move into the opposite-direction lane to pass cyclists safely. If sight distances are limited or if there is traffic coming in the opposite direction, overtaking motorists may need to wait behind cyclists until it is safe to pass. The safety and convenience of rural roads depends on the volume of traffic and the width of the road. If the volume of vehicle traffic is high enough that drivers of wide vehicles are tempted to try to pass cyclists when it is unsafe to do so, then the roadway should be widened to provide proper passing space. Wide (16′ or wider) lanes or wide, continuous, well-maintained paved shoulders can provide additional room for users to share the road more effectively.
New suburban development often extends into previously rural areas, placing higher traffic volumes on inadequate rural roads. It is important to improve these roads to suburban street standards in conjunction with suburban expansion in order to ensure that they perform well for a mixture of traffic types. Rather than widening rural roads in spot locations as their frontage is developed, roads should be improved in a contiguous manner to provide safe, efficient routes for mixed traffic between important trip endpoints.
Zoning and segregation of complementary land uses affects the convenience of utilitarian cycling by increasing trip distances. Allowing residential uses near office developments allows employees to choose to live closer to work. Neighborhood shopping centers that are located within a mile of most residences and adjacent to the highest housing densities will generate the highest levels of bicycle access. Schools and parks located adjacent to or within residential neighborhoods generate more bicycle transportation than larger regional facilities located farther away.
Utilitarian trips by bicycle require a safe place to park the bicycle at trip endpoints. Shopping centers and other important errand destinations best accommodate cycling when they are equipped with bike racks that accept U-locks. Rather than having one large rack for an entire shopping center, multiple small racks located near building entrances will enjoy better utilization and increase convenience for cyclists.
Bicycle commuting in suburbs is especially popular among fitness-oriented cyclists, who need to clean up and change clothes when they reach work. Lockers or shower facilities located on-site are very helpful. For cyclists who commute by bike regularly, sheltered or indoor parking of bicycles is preferable in order to reduce exposure to thieves, vandals, and the elements.Tweet