Officials Urge Use Of Zipper Merge, Drivers Remain Wary

Police and transportation officials are urging Indiana drivers to use what’s called the zipper merge to speed up traffic during the ongoing construction of Interstate 69.

While some drivers are skeptical about the technique’s effectiveness, there’s evidence it increases safety.

Here’s how a zipper merge works: cars use both lanes during backups, then take turns filing into one lane.

Although Indiana hasn’t done any studies of its own on zipper merges, the Minnesota Department of Transportation says the method can relieve congestion by up to 40 percent.

INDOT Public Affairs Manager Andy Dietrick says it’s a challenge getting Hoosiers to believe that.

“The goal of a zipper merge is to fill both lanes to full capacity,” Dietrick says. “And what that does is it shortens the queue or shortens the length of the traffic that is slowed or stopped.”

Dietrick says zipper merges aren’t always the best traffic control methods, but when they are, there will be signs letting drivers know to use them.

That’s the case at several points along I-69 Section 5, where signs direct drivers to use both lanes during backups.