Are drivers required to ‘zipper merge’ in NC, or they can jump ahead? What state law says
Drivers who wait until their lane ends to merge at the last minute may seem rude when they’re jumping ahead of other drivers waiting in line, but studies show that the maneuver can help improve traffic flow.
This type of merge is known as a “zipper merge.”
In 2019, the N.C. Department of Transportation introduced dynamic zipper merges to help keep traffic flowing smoothly in construction zones along busy highways.
But is it always the right strategy?
Here’s what you need to know about zipper merges in North Carolina.
Are zipper merges required by law in NC?
Zipper merges are not required by law in North Carolina.
A bill introduced in the N.C. House in 2021 would have made zipper merges the law, but it did not pass the Senate.
Why are zipper merges beneficial?
Research shows that zipper merges lead to less congestion on the road.
According to a Montana Department of Transportation study, zipper merges can reduce the overall length of traffic backup by as much as 40%. MnDOT has recently led campaigns to promote the use of zipper merges in slow-moving traffic, though the technique’s use is not required by law.
Zipper merges also “improve safety by promoting similar travel speeds between adjacent lanes,” and “help create a sense of fairness and equity because all lanes are moving at the same pace,” according to AAA.
Should drivers always use the zipper merge?
Zipper merges are useful during periods of heavy congestion, but they aren’t recommended when traffic is moving at posted speeds.
When traffic isn’t backed up, “it makes sense to merge sooner into the lane that will remain open,” AAA says.
