Case study · TriMet and Citizen Engineers

How Citizen Engineers showed TriMet's transit signal priority didn't slow other traffic

TriMet extended transit signal priority to bus routes that cross its FX2–Division BRT line in Gresham, Oregon, and had to know what that meant for everyone else on the road. Its consultant, Citizen Engineers, used Flow Labs' probe-based signal performance measures to find out, with no additional field hardware or staff deployment.

• Flow Labs measured control delay by movement, including side streets and left turns, plus arrivals on green and stops for general traffic.
• Citizen Engineers finished the before–after analysis within days instead of weeks of fieldwork, in time for TriMet's fiscal reporting deadline.
• Flow Labs data, combined with the TSP provider's transit data, helps TriMet feel comfortable rolling out transit signal priority on more corridors.