ADOT trying 'zipper merge' on road projects in the West Valley to ease traffic jams

Posted at 9:53 AM, Oct 19, 2016
and last updated 2016-10-20 11:00:12-04

Drivers who wait until the very last moment before merging can make your blood boil, but that is exactly what ADOT wants you to do for a project on I-10 in the West Valley.

It’s called a zipper merge, and crews have used it during peak travel times the past few weekends on westbound I-10 near S.R. 85 where traffic was reduced to just one lane.

So how does the zipper merge work? Instead of drivers merging as soon as they see the signs, drivers will use both lanes for as long as possible and then take turns merging into the open lane at a certain point.

Initial results show this "wait to merge" idea is saving time for drivers in the West Valley.

ADOT also used a zipper merge in Tucson earlier this year. But ADOT says this style of merging only works in certain situations.

“The zipper merge works in very specific road projects,” says ADOT Assistant Communications Director Steve Elliott. “When traffic is already moving slowing into the merge point, merging early can make the queue longer.”

ADOT will continue to look at the data, and we could see the zipper merge in other future projects.