NewsOperation Safe Roads


ADOT develops first-of-its-kind technology to warn of wrong-way drivers

Wrong-way crashes in Phoenix: Detection system catches incidents
Posted at 5:00 AM, Sep 20, 2022

PHOENIX — Two sisters and Grand Canyon University students were at the wrong place at the wrong time. They were killed by a wrong-way driver who was drunk behind the wheel.

"I'll never be a grandma," said their mother, Cathy Hocking, back in 2018. "I'll never plan a wedding. I'll never pick out a wedding dress, every mother's dream with her daughter."

It was April of 2017 when Kelsey and Karli Richardson were traveling on the I-17 near Greenway Road when they were involved in the crash that left their vehicles unrecognizable.

The Arizona Department of Transportation tells ABC15 it was a string of wrong-way crashes that pushed them to look for a solution, and they used technology to do it.

"We really couldn't take it anymore," said ADOT's Doug Nintzel. "We needed to do something."

He says conversations began among the department about what could be done to try and warn law enforcement and commuters about wrong-way drivers entering the freeway.

Nintzel said thermal cameras were brought up. Normally, they are used for traffic signal sequencing. But, the team discovered they also have a feature that can detect a driver going in the inverse direction.

The cameras are not the only part of the pilot program. ADOT said they have added larger wrong-way signs and lowered them. Some even light up to catch a driver's attention. Arrows have been added to the pavement, too.

"It is amazing... something this small can then have a focus across a pretty wide ray or across the entire expansive, an off-ramp, or even the lanes of the freeway itself, and they can detect very reliably that a vehicle is traveling in the wrong direction," Nintzel explained.

The I-17 Wrong-Way Detection Pilot Program was then developed and began in 2018. It was the first in the nation to be able to detect wrong-way drivers in real time. The first phase is a 15-mile stretch along I-17 between I-10 and Loop 101.

ADOT tells ABC15 that the cameras have detected more than 300 wrong-way vehicles on I-17 since 2018. Luckily, many of those drivers have self-corrected before entering the mainline. But it still trigged an immediate alert for first responders to try and catch up to those drivers.

"This is all about alerting us down at the Traffic Operations Center and alerting law enforcement," Nintzel explained. "It's not the same as waiting for 911 calls to come in from other drivers out on the freeway. We get an instant alert."

That is crucial. An analysis from ADOT found that 25% of all wrong-way crashes were fatal in Arizona compared to just 1% of overall crashes on divided highways. When a wrong-way crash occurs, it is more likely to cause more damage.

But they have not been able to duplicate the pilot on other Valley freeways yet. Nintzel said they are in communication with the Maricopa Association of Governments to look at identifying funding options.

"Well, the good news on this is that some of our construction projects, we are able to set aside the funds to add thermal cameras at off-ramps within those areas."

Thermal cameras have been added following road work on Loop 101 (Pima), the new Loop 202 (South Mountain), and Loop 101 (Price), and cameras are to come as the Broadway Curve Improvement Project continues.

The department wants to stress this is a detection system, not a prevention system. It is not foolproof and drivers have to make the right decision out on the roadways with a majority of these wrong-way incidents resulting from impairment.

According to ADOT, in addition to the I-17 Pilot System, thermal cameras are located at off-ramps along the following sections of Valley freeways:

  • I-10 between 27th Avenue and Dysart Road (West Valley)
  • Loop 101 (Price Freeway) between US 60 and Loop 202 (Santan Freeway) in Chandler
  • Loop 101 (Pima Freeway) between I-17 and Princess Drive in the north Valley
  • Loop 101 (Agua Fria Freeway) between 43rd Avenue and Bell Road (northwest Valley) and at the Loop 101 interchanges at Maryland, Northern and Peoria avenues in the West Valley
  • Loop 202 (South Mountain Freeway) between 40th Street (Ahwatukee area) and I-10 (West Phoenix)
  • Loop 303 between Thomas Road in Goodyear and I-17 in north Phoenix
  • I-17 off-ramps between 19th Avenue and 16th Street
  • I-17 off-ramps at Deer Valley Rd (southbound), between Pinnacle Peak and Dove Valley roads and at Daisy Mountain Drive
  • US 60 (Superstition Freeway): At Goldfield, Tomahawk, Idaho Road (SR 88) and Ironwood Drive (Apache Junction region)
  • ADOT also has set existing thermal cameras (for traffic signal sequencing) to detect wrong-way vehicles at intersections along SR 347 in the Maricopa area

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