Why Interstate 17 Accidents Like This Weekend Are Troublesome

July 16, 2013

It happened again on Interstate 17 this past weekend. An accident snarled southbound traffic Sunday afternoon leaving homebound travelers stuck in a massive jam, and geography makes the problem worse. This time the accident was near Black Canyon City. As the name indicates I-17 is routed through a narrow canyon at that point.

Bart Graves is a spokesman for Department of Pubic Safety and said that stretch of highway is particularly tough.

"You have a high volume of traffic coming down from Flagstaff or Prescott and points north, and if they’re going to the Valley most of that traffic will be on I-17," Graves said.

Graves said the first priority at the scene of a crash is to get victims treated and transported, and then investigators need to gather evidence.

And when accidents occur on this narrow stretch of highway, the clean up is also challenging, according to Tim Tait with the Arizona Department of Transportation.

"This crash this weekend had a lot of debris, had (a) fifth wheel trailer that broke into a number of pieces," Tait said. "It required heavy equipment to clear the roadway, and there’s really no easy way to push that off to the side like we can in some other areas."

So traffic inevitably backs up. Tait said if one lane of a two lane highway is blocked for 5 minutes, traffic will back up a mile.

"From a traffic engineering standpoint, we estimate that for every mile of back-up it takes about an hour to clear. That’s just an estimate we use," Tait said.

The 30 mile stretch of I-17 from Cordes Junction to New River has no alternate routes, so travelers caught in traffic jam there have no choice but to wait it out.

Tait said ADOT tries to alert southbound motorists with portable signs and social media advisories before they get to Cordes Junction, but often it is too late.