A coordinated effort to address wrong-way driving on a freeway near San Antonio, Texas, has led to the implementation of an extensive system that includes SmartSensor HD for vehicle detection.

July 15, 2014

SAN ANTONIO, TX—A coordinated effort to address wrong-way driving on a freeway near San Antonio, Texas, has led to the implementation of an extensive system that includes SmartSensor HD for vehicle detection. Analysis of the system has shown a nearly 30 percent reduction in wrong-way driving in the 14 months since the system was implemented.

Wrong-way driving accounts for approximately three percent of all accidents on US freeways, but these accidents can have a fatality rate up to 27 times higher than other high-speed crashes, according to the US National Transportation Safety Board. In Texas, 30 people were reportedly killed in wrong-way collisions between 2007 and 2011. In 2011, TransGuide, the ITS system designed by the San Antonio district of the Texas Department of Transportation, recorded 185 wrong-way driving incidents; while nearly 80 percent of these resulted in no accidents and 13 collisions resulted in no fatalities, a total of seven deaths resulted from just four wrong-way crashes.

These alarming statistics spurred the formation of the San Antonio Wrong-Way Driver Task Force, a coalition of several separate agencies including TxDOT, the Federal Highway Administration, the Texas Transportation Institute and the San Antonio Police Department. Using SAPD and TransGuide logs along with spatial analysis technology created by TTI, the task force was able to identify a 15-mile (24 km) stretch of the US 281 corridor running north from downtown San Antonio as the area with the highest rate of wrong-way driving incidents.

This stretch of US 281 was selected for a pilot project to test wrong-way driving countermeasures. Beginning in 2012, the task force deployed flashing wrong-way warning signs and Doppler detection on exit ramps; recently, several SmartSensor HD units were installed along the mainline to augment the ramp systems and provide detection on the freeway.

The Wavetronix SmartSensor HD detects vehicles in real time and provides authorities with accurate per vehicle speeds as well as direction of travel. When HD detects a vehicle is traveling in the wrong direction, blank LED message signs are activated to display a message to the errant driver; a message is also sent to TransGuide. Wavetronix is represented in the project by Twincrest Technologies, the authorized Wavetronix channel partner in Texas.

So far, the system’s performance is promising. Since July 2012, TxDOT TransGuide logs have shown a 29.11 percent reduction in wrong-way driving events; data provided by SAPD has shown a 29.77 percent reduction in events. TxDOT is evaluating the results of the San Antonio countermeasures pilot in order to create best-practice recommendations that could lead to other similar deployments.