Design and operate intersections to reduce the total amount of time that people—inside and outside of vehicles—spend waiting. Since walking is part of the transit trip, minimizing transit delay also involves a special emphasis on pedestrians. Compact intersections with urban-scale turn radii and pedestrian islands work with these goals, providing safe crossings at all legs of the intersection, while facilitating short signal cycles.
Signal priority can be used both to keep transit runs on time and to reduce scheduled travel time. A combination of transit-friendly base signal timing and conditional priority can promote all transit runs and also manage headways, keeping transit predictable and comfortable for passengers and dispatchers alike. Where “transit first” or mode shift policy directives exist, preferential intersection treatments should be implemented aggressively to promote transit goals, consistent with pedestrian needs.
Signal priority and dedicated lanes are most effective when implemented together. Providing a transit approach lane or a dedicated lane, alongside transit signal priority and in-lane stops, can eliminate delays from general traffic queuing. With dedicated lanes in place, a concurrent transit, through-vehicle, bike, and pedestrian phase can move before vehicle turn phases, making intersections both more convenient and safer. Make these improvements through close coordination between street departments and transit agencies.
Geometrically skewed movements, left turns across multiple lanes, and high-volume right turns can create both injury risks and delays on a transit street. Transit, through-moving vehicles, and people walking and biking can all benefit when problematic vehicle movements are provided with separate signal phases. Keep these and all phases short to prevent long transit and pedestrian wait times.
Use the full palette of intersection design and traffic management techniques to filter vehicle traffic onto and off of transit streets, preventing congestion and improving the street environment. Where dedicated lanes are not possible, periodically diverting private through-traffic or selectively prohibiting turns keeps transit moving. On blocks with stations where space is at a premium, motor vehicle through-traffic or parking can be prohibited altogether, freeing space for other priorities.
Different treatments work for different intersections. Analyze intersections in the context of block length, transit volumes and headways, pedestrian and bicycle volumes and crash history, motor vehicle traffic movements, crossing transit lines, and opportunities presented by the broader street network. Across all contexts, intersection design strategies should prioritize key movements and target the main sources of transit and pedestrian delay.