Transit Signal Priority implemented in Chicago found a 4 to 15 percent reduction in bus travel time, 51 to 54 percent reduction in bus travel time variance, and annual fuel consumption savings of 131 gallons for bus routes 49 and X49.

Field testing of a one-mile segment of Western Ave. in Chicago of transit signal priority.

Date Posted
05/22/2016
Identifier
2016-B01058
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CTA Transit Signal Priority (TSP) Initiative: Evaluation Report for Western Avenue TSP Demonstration

Summary Information

This evaluation was conducted to identify the benefits of transit signal priority (TSP) at 10 TSP-equipped intersections for Route X49 buses and Route 49 buses along Western Avenue in Chicago. The evaluation was performed by comparing the Measures of Effectiveness (MOEs) for travel time, delay, time deviated from schedule, and number of delayed buses before and after TSP implementation. Transit data were collected from the field travel time runs, CTA real-time bus database, and TSP phase selectors for analysis. Percentage difference was used to quantify the improvements for these MOEs.

Methodology

The evaluation focused on transit mobility and reliability and was performed by comparing the Measures of Effectiveness (MOEs) for travel time, delay, time deviated from schedule, and number of delayed buses between before and after signal optimization, and before and after TSP implementation. Transit data were collected from the field travel time runs, CTA real-time bus database and TSP phase selectors for analysis. Percentage difference was used to quantify the improvements for these MOEs.

Benefits

The evaluation results indicate mobility and reliability were improved for Route X49 buses, Route 49 buses, and general traffic on a directional basis during the peak periods on the one-mile segment of Western Ave. (between Lyndale St. and Diversey Ave.) after TSP implementation. Transit benefits included:

  • Average bus travel time was reduced by 15 percent (2 minutes) for southbound X49 buses during A.M. peak and by 4 percent (0.5 minute) for northbound X49 buses during the P.M. peak.
  • Average bus delay was decreased by 24 percent (1 minute) for southbound X49 buses during A.M. peak and by 6 percent (0.3 minute) for northbound X49 buses during P.M. peak.
  • Average bus travel time variance was reduced by 54 percent (1.3 minutes) for the southbound X49 buses during A.M. peak and by 51 percent (1.2 minutes) for northbound X49 buses during P.M. peak.
  • Average time deviated from schedule was decreased by a range of 9 percent to 36 percent (29 seconds to 133 seconds) for northbound X49 buses in A.M. and P.M. peak periods at Diversey and Fullerton.
  • The number of delayed buses was decreased by a range of 20 percent to 60 percent (1 to 7) for northbound and southbound X49 buses during A.M. and P.M. peak periods at Diversey and Fullerton.
  • Annual fuel consumption savings was 131 gallons and annual emissions reduction was 17,737 grams for NO and 484 grams for PM for the total 5 TSP intersections.
Results Type
Deployment Locations