Dr. Michael Knodler Discusses the 'Zipper Merge' for Dealing with Highway Congestion Caused By Lane Closures on NPR.

Wherever you may be driving this summer, there will likely be lane closures for road construction and the need to merge. Traffic engineers have been espousing the "zipper merge" in high-volume construction areas for years. 

Research shows the zipper — which is a late merge, using both lanes as long as possible, not moving over right away — is often safer and will keep traffic flowing. The problem is, among your fellow drivers, it's not the most popular move.

It's also not the easiest to explain.

Read entire article on NEPR.net