Transit Signal Priority systems are widely used to improve transit operations at signalized intersections, but variations in signal display design may affect how drivers interpret and respond to these signals. Although recent updates to the Manual on Uniform Traffic Control Devices revised standards for certain TSP indications, many jurisdictions continue to operate legacy signal designs. The safety implications of these design differences are not well understood.
This project investigates the relationship between TSP signal display configurations and crash outcomes at intersections. The research will develop a national inventory of TSP implementation sites and associated signal design characteristics, compile crash histories for these locations, and analyze crash frequency and severity using statistical modeling. Crash report narratives will also be reviewed to identify behavioral factors linked to specific signal displays. Results will provide evidence-based guidance on transit signal design and support future updates to national standards, improving intersection safety while maintaining effective transit operations.