Arizona’s State Transportation Board has approved a US$3.7m project to construct a first-in-the-nation thermal detection system on Interstate 17, which will monitor wrong-way vehicles and alert the other drivers and law enforcement of them.
Last week, Governor Doug Ducey instructed the Arizona Department of Transportation (ADOT) to accelerate the construction of the system, following a recent spate of wrong-way crashes. Construction of the thermal camera pilot system is due to begin this autumn on I-17 from I-10 to Loop 101, although ADOT is exploring ways to start work even sooner. Full installation will take seven months, and the project’s performance will guide further expansion. The system will take a three-phase approach when a wrong-way vehicle is detected: alerting wrong-way drivers so they can self-correct; warning right-way drivers; and notifying law enforcement.
Once operational, the system will use thermal cameras, warning signs for wrong-way drivers, and advisories for right-way drivers along a 15-mile (24km) stretch of I-17. The system will also automatically focus highway cameras on the wrong-way vehicle, and send automated alerts to the Highway Patrol, helping troopers intercept vehicles faster. On freeway ramps, wrong-way vehicles will trigger alerts, including illuminated signs with flashing lights, aimed at getting drivers to stop. The system will immediately warn other drivers through overhead message boards, as well as law enforcement. Cameras in the area will automatically turn to face the wrong-way vehicle, so traffic operators can better track it. On the freeway, thermal cameras placed at one-mile intervals will signal when a wrong-way vehicle passes, so State Troopers can plan their response and get out in front of it quicker.
While ADOT and the Arizona Department of Public Safety (DPS) respond quickly to reports of wrong-way drivers, most incidents begin with 911 calls from other motorists. The advantages of this system begin with automatically alerting both departments to wrong-way drivers at the point of entry, and getting State Troopers to wrong-way vehicles faster.
Although the system can reduce the risk, it cannot prevent wrong-way driving, and when crashes do occur, research demonstrates that more than 90% of the time, the collision is the result of driver behavior, particularly driving while impaired. Beyond a detection system, coordination with the DPS and local police is necessary to stop and intercept wrong-way drivers before they enter the highway system. ADOT is continuing to study new technologies that could reduce the number of wrong-way drivers.