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.
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.