Ask a Trooper

Sgt. Jesse Grabow of the Minnesota State Patrol

Question: With summer time here and all the construction zones, can you talk about the zipper merge? It’s been talked about for a while but a lot of people don’t seem to get it.

Answer: The late merge of “Zipper Merge” is a driving strategy that requires a change in the mindset of motorists who traditionally have been taught to merge early when recognizing that a lane will end. The results of early merging are longer backups, an increase in crashes and road rage incidents.
The driving procedure to follow is when you see the “lane closed ahead” sign and traffic is backing up, stay in your current lane up to the point of merge. Then take turns with other drivers to safely and smoothly ease into the remaining lane. When traffic is heavy and slow, it is much safer for motorists to remain in their current traffic lane until the point where traffic can orderly take turns merging.

The Zipper Merge benefits drivers by:
• Reducing the difference in speeds between two lanes. Changing lanes when traffic is traveling at approximately the same speed is easier and safer.
• Reducing the overall length of traffic backup by as much as 40%.
• Reducing congestion on freeway interchanges, especially in the metropolitan area.
• Creating a sense of fairness and equity that all lanes are moving at the same rate.
• Reducing incidents of road rage.

A portion of state statutes were used with permission from the Office of the Revisor of Statutes. If you have any questions concerning traffic related laws or issues in Minnesota, send your questions to Trp. Jesse Grabow – Minnesota State Patrol at 1000 Highway 10 West, Detroit Lakes, MN 56501-2205. (You can follow him on Twitter @MSPPIO_NW or reach him at, jesse.grabow@state.mn.us).