I-17 thermal cameras found to be reliable wrong-way vehicle detection system in Arizona

July 8, 2020

An assessment from the Arizona DOT (ADOT) has found that the pilot I-17 thermal camera system in Phoenix has proven to be a reliable way to detect wrong-way vehicles, alert law enforcement, and warn other drivers to reduce the risk of crashes involving often-impaired wrong-way drivers.

ADOT has already expanded use of the technology, with plans to do more as time and funding allow. The assessment includes recommendations for components to be added at urban and rural locations as funding becomes available. 

The assessment found that compared to waiting for 911 calls from other drivers, the immediate alerts provided by thermal camera detections result in faster response times by law enforcement. 

“The I-17 pilot system has delivered positive results and helped provide a road map for expanding use of technology to reduce the risk from wrong-way drivers,” Dallas Hammit, ADOT’s state engineer and deputy director for transportation, said in a statement. “We’re using the thermal camera technology elsewhere and have established plans for other areas, including rural locations.”

The thermal camera detection technology that is key to the I-17 system has now been installed at most interchanges along the Loop 202 South Mountain Freeway. Installations are underway along Loop 303 in the West Valley, and the technology will be added as part of Loop 101 expansion projects that are under construction east of I-17 and also south of U.S. 60.

The $4 million I-17 pilot system was funded by Proposition 400, the dedicated sales tax for transportation improvements approved by Maricopa County voters in 2004. Since the system began operating in January 2018 between the I-10 “Stack” interchange and Loop 101, it has detected more than 100 vehicles traveling the wrong way, mostly on exit ramps and frontage roads along the Black Canyon Freeway. 

The alert system also features specialized internally illuminated wrong-way signs with flashing LED lights along I-17 off-ramps, designed to get the attention of a wrong-way driver.