Transit Signal Priority
Continuous Operation Monitoring
RTD and the participating stakeholders are now monitoring the TSP operation to make sure the systems are all functioning as intended. This is accomplished by analyzing and comparing the data retrieved from 1) bus on-board log, 2) relay log, and 3) traffic controller log. The preliminary results show that, in general, the TSP systems are functioning as designed.
Project Overview
Summer 2020 - Present
About TSP
Transit Signal Priority (TSP) is considered to be one of the popular transit management strategies that can be used to help transit service become more reliable, faster, and more cost-effective. TSP has little impact on general traffic and is a relatively inexpensive way to make transit more competitive with the automobile. Transit signal priority modifies the normal signal operation process to accommodate transit vehicles better. RTD acknowledges TSP as one of the advanced tools to improve bus speed and reliability. Consequently, RTD developed a new TSP operating concept, and the designed TSP concept has been deployed at 18 intersections in the district to improve transit service and performance.
TSP Concept of Operations
Typically, TSP operation allows traffic signal controllers to skip conflicting signal phases, to shorten conflicting phases, to lengthen compatible phases, or to modify phase sequence to serve the transit vehicle. Two primary TSP strategies are 1) Green Extension and 2) Early Green (Red Truncation). More specifically:
- A green extension strategy extends the green time for the TSP movement when a TSP-equipped transit vehicle is approaching. The green extension is one of the most effective forms of TSP since a green extension does not require additional clearance intervals.
- An early green strategy shortens the green time of the preceding phases to expedite the return to green (i.e., red truncation) for the movement where a TSP-equipped vehicle has been detected. This strategy only applies when the signal is red, and a TSP-equipped vehicle is approaching. Both green extension and early green strategies are available together within TSP enhanced control environment but are not applied to the same signal cycle.
TSP Application Reference Materials and Contact Info
An "RTD Transit Signal Priority (TSP) Application Guidelines" has been prepared and published. The application guidelines explain what TSP is, why it is important, what the benefits are, and the important issues surrounding the topic. This report contains the steps one should follow to implement a TSP project in the district successfully. To request a copy of the report or have any other Transit Priority questions (e.g., TSP, Queue Jump, Bus Bypass), please email [email protected].