Transit Signal Priority

Transit Signal Priority (TSP) utilizes existing vehicle location and wireless communication technologies to advance or extend the green light of a traffic signal to allow a CTA or Pace bus to continue through an intersection when the bus is running behind schedule—helping to reduce travel times and ensure on-time arrivals.

TSP is being deployed along 13 priority corridors to help CTA and Pace buses travel along 100 miles of roadway and through about 500 intersections operated by the Illinois Department of Transportation (IDOT), the Chicago Department of Transportation (CDOT), and other local departments of transportation throughout the region.

The RTA is leading this regional coordination effort, known as the Regional Transit Signal Priority Implementation Program (RTSPIP), in collaboration with the transit and highway agencies listed above. Funded by a $40 million Federal CMAQ Grant, the overall goal of this program is to develop and implement a regionally-interoperable TSP system that works for both CTA and Pace buses traveling on roadways.

Transit performance will be measured by travel times along TSP corridors, travel time variability, the amount of delay and number of stops at traffic signals, and the impact of TSP on general vehicle travel times. The Evaluation Report for the Regional Transit Signal Priority Implementation Program (RTSPIP) includes a summary of the program goals and objectives, describes how TSP has been implemented in the Chicago region, and documents the TSP performance measures that have been collected and evaluated to date. Additional information on previous program activities is available here.

Current Program Activities

  • The CTA and CDOT implemented TSP on Western Avenue (Howard Street to 79th Street) in 2019. Initially, the CTA utilized the Jeffrey Jump TSP Message Set, pending their interoperability testing of the Regional TSP Message Set. After successful completion of that testing on South Ashland Avenue and Western Avenue in 2021, CTA and CDOT are now updating the software on the buses and at the intersections to utilize the Regional TSP Message Set.
  • Implementation of TSP on the northern and central portions of Ashland Avenue (Irving Park Road to Cermak Road) requires traffic signal modernization, for which the CTA has obtained additional CMAQ funding that will be combined with the RTA's CMAQ grant for TSP. Engineering for TSP and traffic signal modernization on those portions of Ashland Avenue is currently underway, with implementation by CTA and CDOT anticipated to begin in early 2023.
  • Pace installed TSP equipment on portions of Milwaukee Avenue (Golf Road to Jefferson Park CTA/Metra) in 2019, as part of their Pulse Milwaukee Line project, and completed their TSP proof-of-concept testing in early 2021. The proof-of-concept testing on Milwaukee Avenue (involving Pace, IDOT and CDOT) tested the interoperability of the Regional TSP Message Set with different traffic signal controllers utilized by the various DOTs in the region.
  • After successful completion of testing on Milwaukee Avenue, Pace began installing TSP on additional corridors throughout the region – beginning with Dempster Street in 2021 and continuing through 2022 on the other corridors listed above.


CTA and Pace bus service is getting more reliable! Using proven technology, Chicagoland transit agencies are deploying a fully integrated Transit Signal Priority (TSP) system for bus routes on strategic corridors.

Integration of TSP technology on CTA and Pace buses will provide riders with improved on-time dependability and reduced travel times.


Almost 50 percent of the region’s transit riders can benefit from faster, more dependable bus service. On TSP-equipped buses, riders will see fewer traffic signal delays, enabling them to reach their destinations on time—with minimal interruption to the flow of regular traffic. In fact, traffic signal synchronization will be improved along these corridors as part of the TSP program. As bus service improves, ridership numbers are expected to grow as people see bus transit as a more attractive travel option, thus helping to reduce the region’s gridlock and improving air quality.


TSP is an important component of the Bus Rapid Transit (BRT) and Arterial Rapid Transit (ART) systems being developed and deployed in the Chicago region.

Thirteen priority corridors have been selected based on several key factors including bus ridership, geographic location, and network connectivity.


  • Ashland Avenue
  • Western Avenue


  • 159th Street
  • 147th Street/Sibley Boulevard
  • 95th Street
  • Cermak Road
  • Cicero Avenue
  • Dempster Street
  • Grand Avenue (in Lake County)
  • Milwaukee Avenue
  • Roosevelt Road
  • Halsted Street/Harvey
  • I-90 Transit Corridor Access


A regional TSP system that works for both Chicago Transit Authority (CTA) and Pace buses is being deployed on roadways maintained by Illinois Department of Transportation (IDOT), Chicago Department of Transportation.

In 2016, CTA and CDOT implemented TSP on South Ashland Avenue between Cermak Road and 95th Street.

Pace has already implemented optimized signal timing in the following corridors:

  • 147th Street/Sibley Boulevard
  • 159th Street
  • 95th Street
  • Cicero Avenue
  • Grand Avenue (in Lake County)
  • Roosevelt Road Signal optimization is the first phase of TSP installation and allows buses to travel faster.


The Regional Transportation Authority of Northeastern Illinois (RTA) is leading the coordination of this regional program. Leading implementation and construction are the CTA, Pace, IDOT, CDOT and other local and county transportation agencies. The RTA is ensuring that a seamless and integrated TSP system is implemented across the different transit and highway jurisdictions.


The RTA’s $40 million program for TSP deployment includes approximately $36 million in federal Congestion Mitigation and Air Quality Improvement Program (CMAQ) funds and $4 million in RTA funding. These funds are being combined with other federal grants to the CTA and Pace for specific corridors.


In 2019, CTA and CDOT implemented TSP on Western Avenue between Howard Street and 79th Street. They are currently designing TSP improvements for Ashland Avenue between Irving Park Road and Cermak Road.

In 2019, Pace implemented TSP on Milwaukee Avenue, between Golf Road and Jefferson Park CTA station, as part of the Pulse Milwaukee Line Project. After completion of TSP testing on Milwaukee Avenue in early 2021, Pace began implementing TSP on other corridors beginning with Dempster Street.

Learn more about TSP deployment and the Green & Go program