Arterial signal coordination is the process of adjusting the timing of traffic signals along an arterial road so that vehicles can travel through the corridor with minimal stops. This can improve traffic flow, reduce delays, and improve safety.

There are a number of different ways to evaluate arterial signal coordination. The two commonly used methods are (1) to use vehicle trajectories through either manual floating-car runs or vehicle telematics, and (2) to use automated traffic signal performance measures (ATPSMs). ATPSMs are a set of metrics that can be used to evaluate the performance of traffic signal systems. One of the most important aspects of signal performance is coordination, and the percentage of vehicles that arrive at a signal on red (%AoR) is one of the major parameters. %AoR is a good measure of signal coordination at a single intersection, but it does not provide a complete picture of corridor-level performance. Another graphical representation of the %AoR is the Purdue Coordination Diagram. It provides a visual illustration of the quality of progression on individual intersection approaches.


LTAP Recorded Webinar Image

In this presentation, we will show how automated trajectories from vehicle telematics can be used to improve the evaluation of signal coordination. We will use a real-world case study to show how %AoR and trajectory-based stops are correlated, but not always consistent. We will also introduce the concept of the Corridor Synchronization Performance Index (CSPI), which is a corridor-level metric that can be used to evaluate signal coordination.

Upon completion of this course, participants will be able to:

• Understand the concept of signal coordination and its importance for traffic flow
• Identify different methods for measuring signal coordination
• Use vehicle trajectories to improve the evaluation of signal coordination
• Calculate and interpret the Corridor Synchronization Performance Index (CSPI)
• Apply the concepts of signal coordination and CSPI to real-world case studies

Instructor Bio

Dr. TianDr. Zong Tian is an internationally recognized expert in traffic signal control. He is currently a Professor and Director of the Center for Advanced Transportation Education and Research (CATER) at the University of Nevada, Reno (UNR). He obtained a Ph.D. degree from Texas A&M University (2004) and had previously worked at Kittelson and Associates, Inc. (1995-1999) and the Texas Transportation Institute (2000-2004). Dr. Tian is active in several transportation professional organizations. He served as a committee member for two major committees of the Transportation Research Board (TRB): the Highway Capacity and Quality of Service Committee, and the Traffic Signal Systems Committee. He is the Topic Area C Manager of the World Conference on Transport Research Society (WCTRS), overseeing the society’s four special interest groups in the area of urban traffic control, system operations, ITS, and safety. His specialty area is in traffic signal systems and operations, highway capacity, and integrated freeway and arterial operations. He received the Young Consultant Award from ITE in 1997. He has more than 80 referred journal publications with the majority in the area of signal control and highway capacity analysis. He has published two books titled “Integrated Diamond Interchange Ramp-Metering Traffic Control Systems” and “Global Practices on Traffic Signal Control”. Dr. Tian invented the state-of-the-art TranSync tool for improving the state of practice in signal timing and coordination.


To earn Professional Development Hours (PDHs) or a Certificate of Completion for each recorded webinar, you must view the entire webinar. After viewing, please fill out the web form at the link below to request your certificate. The Florida LTAP Center will follow-up within 2-3 weeks.

This webinar will award 2.0 PDHs.

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