Traffic Signal Automated Performance Measures

The Utah Department of Transportation is using data from SmartSensors Advance and Matrix in an innovative program that publicizes the performance of signalized intersections.

Project Team

The Utah Department of Transportation; Dr. Darcy Bullock, professor of Civil Engineering at Purdue University and director of the Joint Transportation Research Program; and Indiana Department of Transportation.

Project Scope

The Utah Department of Transportation manages 1,150 of Utah’s 1,900 traffic signals. Eighty-seven percent of UDOT signals and 76 percent of non-UDOT signals share a single communications network, including around 750 which are actively monitored by either SmartSensor Advance or SmartSensor Matrix. UDOT wanted to exploit this connectivity to proactively monitor and optimize traffic signals and make traffic data available to anyone who wants it.

Problems and Challenges

Working to build a world-class organization, UDOT recognized they couldn’t always build their way out of traffic problems. But developing a signal system sophisticated enough to create proactive traffic plans required a series of metrics built on accurate and reliable traffic detection, including advance detection upstream of the queue and lane-by-lane count detection.

At intersections, UDOT faced three specific challenges. First, signal plans can be costly and may lose value over time as traffic patterns change and evolve. Second, because intersections were not continuously monitored, UDOT had to rely on customer complaints to know if intersections were not operating properly, and this often led to miscommunication about the true nature of the problem. And third, previous systems forbade users without access to software and passwords from utilizing traffic information.

Solution

Working with UDOT, Wavetronix optimized Advance and Matrix to allow the transfer of raw data directly from traffic signal controllers to an eight-terabyte UDOT server using an FTP connection, bypassing the need for a central traffic management system. This real-time data populates a series of metrics that provide instant information about intersections to traffic engineers, allowing proactive solutions to traffic problems.

The Utah Department of Transportation manages 1,150 of Utah’s 1,900 traffic signals.

Benefits

Wavetronix sensors operate 24 hours a day and require no routine maintenance, allowing for constant reliable data. UDOT’s Traffic Signal Automated Performance Measures system was implemented in January 2013, and in the first twelve months of use UDOT proactively found and fixed more than 100 detector problems, 35 time-of-day errors and 40 incorrect traffic offsets for better progression. Today, UDOT claims that only one in four vehicles encounter a red light on UDOT roads. The program has also been recognized by the American Association of State Highway and Transportation Officials, who presented UDOT with a 2013 Group Focus Award.