06/15/2026
Not all work zones are set up as zipper merges. When they are, the signs are very clear and specific. It’s not always the preferred method but they can be very effective when drivers read the signs, cooperate and are courteous to other motorists. Drivers should never block lanes or try to control traffic. It’s dangerous, illegal and accomplishes nothing.
Zipper merge work zone signs are quite clear: Drivers should use both lanes and take turns at the clearly signed merge point.
Work zones in general are dynamic and change throughout the day based on traffic volumes. When traffic is light, vehicles can get to the open lane without issue. But when things get congested and jam up, zipper merges are effective in reducing backups. Instead of 1,000 cars in one lane you’ve got 500 cars in each lane. This prevents backups to adjacent interchanges and curves that might reduce line of sight. Plus, when drivers take turns at the merge point, it takes all the guesswork out and creates a safer, better flow of traffic within the lane closure.
