962. Crash with injuries. Wrong-way driver.
It’s a radio call state troopers respond to all too often.
Since January, the Department of Public Safety says there have been 10 serious wrong-way crashes on Arizona highways. On average, eight people die in wrong-way collisions each year, according to the Arizona Department of Transportation.
To many, the solution seems obvious: install one-way spike strips at the edge of every freeway off-ramp to puncture the tires of cars going the wrong way.
But ADOT Director John Halikowski spiked the idea in a blog post last month.
“Based on our research, it doesn’t look like tire spikes are used anywhere on a highway to stop wrong-way drivers,” he wrote. “This issue is more complex than a parking lot security device can offer.”
Halikowski pointed to a study by the Texas Department of Transportation, which found at least 10 problems with using tire spike strips on freeways.
First, tire spikes are designed for use at slow speeds. Tire spike manufacturers suggest no more than 5 miles per hour, the study found.
“There is no manufacturer out there that makes anything that's going to run at 45 miles an hour that is going to be sustainable, that's not going to break,” said ADOT Division Director for Infrastructure Delivery and Operations Steve Boschen.
Under the volume and speed of freeway conditions, the Texas study found the spikes broke down, leaving stubs that could damage the tires of drivers going the right way.
But maybe the biggest thorn for the spike strip solution was that it didn’t actually stop wrong-way drivers. The Texas study found the spikes did not deflate tires fast enough to actually keep a vehicle from getting on the freeway. The authors tried to modify the shape of the spikes without success.
“They just don’t work,” Boschen said.
Instead, Boschen said ADOT has installed larger, lower “do not enter” signs on 100 freeway ramps, and is experimenting with high-tech solutions.
The department is looking into sensors on ramps that could detect wrong-way drivers, light up flashing “wrong way” signs, and alert authorities, he said. The technology is used by several states, including Texas and Florida, Boschen said.
ADOT is also trying to develop a first-of-its-kind approach: reprogramming the car counters in freeway pavement to detect vehicles going the wrong way.
“We could instantly mobilize someone to the scene and light up our DMS, our digital message boards” with messages alerting drivers in danger, he said.
Boschen said engineers started working on the code a few months ago and are still trying to iron out some false detections, but the department hopes to have both sensor technologies ready in prototype form next year for testing along a stretch of I-17.
“We will continue to research and employ available engineering methods that could deter wrong-way driving. But the fact remains that driver impairment is a major contributing factor,” wrote Halikowski. “There might not be a solution to wrong-way driving, but through technology and innovation, we can strive to reduce the risks.”
You can view an interactive chart on wrong-way crashes by clicking here.
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