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Are Adaptive Signal Control Systems a Solution to Urban Congestion?

Date: 04/15/2015, 1:00pm to 2:00pm
Speaker: Dr. Zong Tian
Organization: University of Nevada Reno
OST-R Office: University Transportation Centers (UTC)


Adaptive traffic signal control systems are an emerging technology for urban arterial operations. This presentation focuses on the current status of adaptive traffic signal control system applications in the U.S. An overview of adaptive signal system deployments is first presented. Some insights of the advantages and drawbacks will be given. The results from some field before-after studies will be discussed. One particular issue is related to how a comparison is made against conventional coordination methods that run pre-defined timing plans on a time-of-day basis. Potential biases can result if a comparison is against non-optimal time-of-day coordination plans. The second part of the presentation introduces some case studies on conventional signal coordination with the assistance of modern technologies and tools. In particular, an iOS-based software tool is demonstrated to show its applications on timing issue diagnostics and performance evaluation. This tool is expected to greatly assist traffic engineers in developing and implementing high quality and cost-effective coordination plans.


Dr. Zong TianDr. Zong Tian is currently an associate professor and director of the Center for Advanced Transportation Education and Research (CATER) at UNR. He also serves as the director of SOLORIS, a Tier 1 University Transportation Center (UTC) consortium that includes four universities across three states: Nevada, Arizona, and New Mexico. He obtained his Ph.D. degree from Texas A&M University.  Prior to joining the University of Nevada Reno in 2004, he held a position of associate research scientist at the Texas Transportation Institute between 2000 and 2004. He was employed at Kittelson and Associates, Inc. in Portland, Oregon between 1995 and 1999. Dr. Tian received the Young Consultant Award from ITE in 1997.

Sponsored by: Office of the Assistant Secretary for Research and Technology (OST-R), University Transportation Centers Program

DISCLAIMER: The views, opinions, findings and conclusions reflected in this presentation are the responsibility of the authors only and do not represent the official policy or position of the USDOT/OST-R, or any State or other entity.

For more information, contact Denise E. Dunn at

Last updated: Friday, June 16, 2017