DURHAM (WTVD) -- NCDOT and North Carolina State researchers are studying the effectiveness of the "zipper merge." The rather unique sign was installed 2 weeks ago where NC 147 meets southbound I-85.

CARS.COM — When it comes to the controversial congestion-management measure known as the zipper merge, convincing motorists still isn’t a snap. But as a growing roster of states report success with ...

Zipper merging is still a tough sell for many in Washington who believe drivers moving into traffic correctly are simply cutting the line. Maybe Washington state needs to take a page from Montana to ...