Global Street Design Guide Designing Streets for People Designing for Transit Riders Transit Facilities Geometry

Global Street Design Guide

Geometry

Side-Running Dedicated Transit Lanes

The recommended width for a siderunning dedicated transit lane is 3–3.3 m. Transit lanes, unlike on-street transitways, are not physically separated from other traffic. Lower capacity systems can allow for adjacent parking and loading lanes when coupled with curb extension transit stops to allow in-lane transit boarding.

Side-Running Transitways

Placing a transitway in an exclusive space separated by vertical elements such as medians improves travel times and predictable movement by reducing conflicts with parked cars, cycles, and some turning movements. Side-running transitways are applicable for highfrequency transit service, especially bidirectional service where turns and curb cuts across the transitway are very limited. To avoid conflicts with transit vehicles, left- and right-turning traffic must be prohibited or accommodated using turn lanes with dedicated signal phases. Widths of 3.3–3.5 m are recommended, as are complementary elements such as all-door boarding, transit signal priority, and level boarding.

Center-Running Transitways with Center Boarding

Center- running transitways can serve BRT and LRT with potentially very high capacities and frequencies. Center loading allows the use of the same platform for trips in both directions and reduces construction costs. The recommended station width is 3.6 m or greater. Center lanes eliminate conflicts with curbside loading, parking, and drop-offs, and require passenger doors on the driver’s side of the transit vehicle. To avoid conflicts, turns across the transitway should be prohibited or accommodated using turn lanes and signal phases. Lanes should be 3.3–3.5 m wide, and at-grade crossings should be provided at frequent intervals to ensure access from both sides of the street.

Center-Running Transitways with Passenger-Side Boarding

Center-running transitways are separated from other vehicle traffic by medians, while side-loading accommodates right-side boarding buses or light rail systems. Center-median transitways provide high-capacity and reliable service, and requires a width between 10–12.5 m, depending on how stations are staggered. Installation should be coordinated with land use changes that maximize potential for transit-oriented development.

Shared Transit Streets

Shared transit streets share priority between transit and pedestrians, operating in car-free streets. Typically designed for busy blocks of commercial or neighborhood corridors, shared transit streets may allow restricted vehicular access and deliveries at specific hours. Most commonly designed with light rail or tram systems, they can also accommodate bus and BRT. Transit vehicles run in a predictable, dedicated path, flush with adjacent pedestrian surfaces, except at transit stops where raised platforms facilitate level boarding. Speeds are reduced generally to 10–20 km/h to facilitate pedestrian permeability across the street and support a quality public space.

Adapted by Global Street Design Guide published by Island Press.