Road design should account for bicycle needs. A bicycle should be a design vehicle, which means planners should consider its operational needs during road design. Since roads are generally designed for wider and faster vehicles, most roads can also accommodate cycling. This basic principle forms the foundation for safe cycling infrastructure. Despite this, a few specific considerations can make a road much safer and more convenient for cyclists.
Special Considerations for Cyclists
Surface Quality: A smooth asphalt surface is crucial for a cyclist’s safety and comfort. Roads must be free of holes and bumps, as these can cause a cyclist to lose control. Regular maintenance is essential to prevent these hazards from developing over time.
Holes and Ridges: Slots parallel to the road, like some drain grates, can trap a bicycle wheel and cause serious falls. Ridges parallel to the roadway, such as railroad tracks and bridge joints, also pose a significant risk. Road crews must fix these defects to create a safer environment for cyclists.
Slippery Metal: Metal surfaces on roads, such as bridge decks or manhole covers, become extremely slippery when wet. Bridges with metal decks should have a concrete section to provide traction. When road work requires metal plates, these should be placed out of the way of a cyclist’s normal route. If that’s not possible, road crews should install clear warning signs to alert cyclists to the hazard.
Traffic Light Activators: Traffic detectors should be sensitive to bicycles. Planners should place these detectors where bicyclists wait for a light to change. If a detector is not sensitive enough, a cyclist may have to wait for a car to trigger the signal, causing unnecessary delays. Traffic signal timing should also provide cyclists enough time to safely clear an intersection, especially if they enter on a yellow light.
Lane Width: Lanes should be wide enough for cyclists and motorists to share safely side by side. A minimum width of 14 feet is needed for this. This space includes any smooth, paved shoulder. When on-street parking exists, the combined width of the parking and travel lanes should be 24 feet. This is the preferred width, with 22 feet being the minimum. On roads that are too narrow to share, a “Share the Road” reminder sign can encourage motorists to travel in the middle of the lane, signaling that cyclists may also do so for their safety.
Safe Intersection Design
Intersections: Intersections pose unique challenges for cyclists. Designers should ensure that sightlines are clear, allowing both cyclists and drivers to see each other. Special signal phases for cyclists can reduce conflicts, though they may increase wait times. Bike lanes should also be designed to guide cyclists safely through an intersection, especially when there are right-turn-only lanes.