CDTA is adding, or upgrading, Transit Signal Priority equipment at 22 intersections as part of the Purple Line project. Transit Signal Priority (TSP) has been utilized along BusPlus corridors for years with more than 115 active locations. TSP enhances traditional transit service by helping to keep buses moving through busy intersections. Put simply, TSP technology allows buses to make traffic signals stay green longer or turn from red to green quicker, reducing the amount of time buses are stopped at traffic lights.
Technology in the vehicle communicates with the traffic signal as the bus approaches an intersection. The system will detect the presence of a bus AND predict its arrival time to the intersection. Using variables including traffic volumes, traffic signal cycle length and pedestrian activity - the TSP system will determine whether to extend the green signal longer or call a green phase sooner.
There are many other benefits to TSP, but the main one is that is reduces transit delays significantly, increasing efficiency of bus travel. It also improves reliability of the network by reducing the amount of times buses are waiting at red lights. TSP can reduce travel time by as much as 10% and help reduce delays by as much as 50%.
Once the Purple Line work is complete, CDTA will have TSP equipment at over 140 intersections in the region, including numerous active installations on Red Line and Blue Line.