What is TSP?

Transit Signal Priority (TSP) is a system that prioritizes buses and improves trip efficiency. 

TSP determines when a bus is approaching a stop light intersection then holds a green light to allow a bus to get through, improving on-time performance and providing a better rider experience.

Deploying Intelligent Transit Signal Priority (iTSP) for SamTrans in East Palo Alto

iTSP Pilot Evaluation

SamTrans, with Sustainable Silicon Valley (SSV), City/County Association of Governments of San Mateo County (C/CAG), and the City of East Palo Alto recently completed the six-month pilot of an intelligent cloud-based transit signal priority system (iTSP) on University Avenue in East Palo Alto. 

The pilot period, from November 2021 through February 2022, included three intersections in the City of East Palo Alto and was funded through a C/CAG grant. 

The primary difference between iTSP and “conventional” TSP, such as the one operating on El Camino Real, is that iTSP is a cloud-based platform that uses an algorithm to dynamically request signal priority when a vehicle is expected to arrive at an intersection. These predictions are based on past travel time data and account for current conditions. They also include a machine-learning component to predict travel time more accurately. 

By comparison, a conventional TSP system requests priority when a vehicle arrives at an intersection. Because iTSP is cloud-based, it communicates with signals using the existing network infrastructure and can record the signal’s operational status. iTSP has a robust set of monitoring and reporting features with typically lower set-up costs due to minimal additional signal hardware.  


Benefits & Timeline

During the pilot, staff observed improvements in average SamTrans vehicle speed and intersection delay. In the northbound direction, iTSP reduced intersection delay by 45% and increased average speed by 18%, mostly at the left turn from University Ave. onto Bay Rd. 

In the southbound direction, iTSP reduced intersection delay by 18% and increased average speed by 7%. 

Lessons and experiences from this project will serve as a blueprint for future capital investments in the SamTrans network and inform staff for future countywide TSP projects that can improve service and rider experience.  


Project Start: May 2021

Pilot in Operation: November 2021 - March 2022

Project End: March 2022

The El Camino Real Bus Speed and Reliability Study (ECR Study) analyzes the impact of slowdowns on SamTrans bus service on El Camino Real and identifies potential changes to achieve faster and more reliable service.