Safe In 60: Merging Late May Seem Impolite – But Allowing It Could Save You Time

WEST VALLEY CITY, Utah – When you see a “lane closed ahead” sign, are you the type of driver who immediately turns on your blinker and tries to merge early, or do you stay in your lane and zoom to the front of the line and merge at the last minute?

The debate definitely sparks strong opinions. The latter option can seem selfish and even rude. But many traffic experts agree: In heavy traffic conditions, the late merge or zipper merge is the correct way to handle a lane closure.

While it seems more polite to merge early, the early-mergers can create a single long, slow line of traffic that is less efficient and can block off-ramps or intersections.

The late merge or zipper merge is when drivers use both lanes fully until they reach the end of the lane, then alternate every other car, like a zipper, into the open lane. It maximizes road space and keeps traffic moving, preventing a long backup that potentially cause more problems down the line. In fact, it’s proven to reduce congestion by 50%.

By eliminating any question of who should yield, it also results in fewer accidents.

Lane zippering works best in heavy traffic. If traffic is light and moving freely and at higher speeds, it is fine to merge early.

Several states have run campaigns to try to retrain drivers to use the zipper merge. Minnesota has been at the forefront of that education campaign. So far, the Federal Highway Administration has not taken an official stance, although their website does highlight the benefits.

It can seem counterintuitive. You would never cut in line at the grocery store or bank, so it can make your blood boil to see cars zipping by to merge at the last minute. But before you take it upon yourself to enforce societal norms by straddling both lanes to block those cars zipping by, just remember – by blocking the late merge, you’re actually making traffic worse.