Design evaluation of bus cross-traffic turn priority box

Cross-traffic turns (left turns in right-hand traffic) significantly delay buses at intersections, reducing transit reliability. This study introduces the Bus Cross-Traffic Turn Priority Box, a design that allows buses to bypass turn queues by using through lanes and enables the pre-acceleration of turning traffic when no bus is present. Microscopic simulations conducted at three intersections (a stylized three-way intersection, a stylized four-way intersection and a real-world intersection using observed traffic data) demonstrate substantial delay reductions for buses and minor improvements for general traffic. Unlike traditional bus priority measures, this approach requires minimal infrastructure changes and enhances overall intersection efficiency, supporting its adoption in space-constrained urban settings to improve public transport performance without adversely affecting other road users.