Ask a Trooper: Zipper merge is not law, but is recommended

Q: Could you explain the zipper merge for merging into construction zones in Minnesota? Is it law or just a rule of thumb? The Minnesota Department of Transportation website explains some of this, but leaves out some information. Also, I have tried using the zipper merge many times. It seems that hardly anyone else on the road knows about it. While doing it, I seem to irritate many other drivers that have merged into the open lane way before the actual merge. Even to the point of being blocked from proceeding in the lane that is about to close. If another driver intentionally blocks a lane, isn’t that impeding traffic? What are the fines for impeding traffic?

A: The “zipper merge” is a Department of Transportation idea. It is not necessarily law, but it is “within” the applicable laws for that situation and it is more than just a rule of thumb. It is what we are teaching drivers. This came about several years ago and is getting a lot more attention as years of education and experience come to fruition. More people are finding out about it all the time and it will get better as time goes on. Hopefully this will help.

As an example, if you are driving in the right lane on a four-lane highway and you see a “left lane closed ahead” sign, be prepared to allow those vehicles in the left lane to come over into the right lane. Keep in mind that the left lane is open until it is actually closed. That means vehicles can legally stay in that left lane until they reach the spot where there are barrels, barricades and usually a “merge here” type of sign. Then, the left and right lane vehicle drivers should take turns getting through that merge spot, in a “zipper” type format. This is what we all need to do to prevent road rage and to make traffic flow smoother, even if you don’t agree with it.

Some people have argued that it slows down traffic more than just letting everyone fend for themselves and that we should make everyone get into the right lane sooner (in that example). Studies show that the “zipper merge” works the best to keep traffic flowing, especially when there is a lot of traffic. The “zipper merge” also helps prevent road rage from drivers who intentionally drive slow in the lane that is closing, and blocking other drivers from passing or getting through. That is against the law. Lane blocking or impeding traffic fines are about $139 and the offense goes on your driving record. We are watching out for lane blockers in all situations.

Q: Who has the right of way when a car is merging on the freeway from an on ramp that does not have a yield sign? Is the law different for cars and motorcycles?

A: A vehicle merging onto another roadway normally is the one that is required to yield, but that does not mean the vehicles already on the road should not move over and assist the merge when possible. There is no difference for cars or motorcycles on merging, except it is a lot more dangerous for motorcyclists. Merging vehicles should try to match the speed of the traffic already on the roadway, stay near the right fog line as long as possible and should let that fog line “bring them into the lane.”

Sgt. Curt S. Mowers is a regional public information officer for the Minnesota State Patrol.

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