(College Station)—A number of other technologies exist to help regulate flow at intersections, and the Texas Department of Transportation (TxDOT) is using several of them already. TxDOT sponsored a project, Cost Effective Technologies for Advance Detection at Signalized Intersections, to investigate which technologies might be most useful and cost effective when feeding data to algorithms developed by TTI.
TTI researchers installed and evaluated various detector technologies for their effectiveness in providing data to the algorithms that help to manage intersections. The intersection of South Highway 6 and FM 185 in Waco was selected as the test bed for the project. Not only do the technologies differ in how accurately they detect traffic, but they also vary significantly in cost to taxpayers. Even so, cost isn’t the most important issue.
“It’s not simply about finding the most efficient or cost-effective system,” explained Srinivasa Sunkari, associate research engineer at TTI. “Promoting safety is even more important. Providing algorithms with accurate and consistent data is one way to promote safety and efficiency at signalized intersections.”
Researchers found that ILDs using contact closure radios were very accurate in counts, vehicle classification and speeds, the three pieces of data needed by the algorithms to most effectively regulate intersections. The other detection systems were of varying value compared to the ILDs. While the ILDs cost less than their counterparts on single-lane approaches, all the systems were cost competitive for two-lane approaches.
Researchers made several recommendations to TxDOT, including installing nighttime lighting and improving their technology to provide speed and vehicle length for each vehicle. Finally, they recommended that engineers consider the overall life-cycle cost of the detection system and not solely the installation costs.
“This research has guided us toward a comparison and selection process
that can be applied to each individual location to address unique field conditions,” said
Davis Powell, TxDOT’s director on the project. “TxDOT is already
benefiting from the research in an Advance Warning of End of Green project
in the Lubbock District. 