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It's Better to Zipper Merge

The City of London is embarking on a campaign to show motorists a better way to merge when a lane closure is happening up ahead and traffic is congested.

Upon seeing a sign indicating a merge, some drivers immediately attempt to change lanes into the bottleneck, creating a long single line of traffic.  Others race up to the front of the lane that’s closing past all the lined up traffic, and merge in at the last second.  Both types of drivers are equally convinced their way is best.

“Transportation specialists agree the best approach is the one that benefits everyone: a zipper merge,” says Edward Soldo, Director of Roads and Transportation for the City of London.  “Zipper merges keep traffic flowing and reduce wait times.”

A zipper merge is when motorists use both lanes of traffic and drive up to the end where the defined merge happens, then alternate in zipper fashion into the open through lane.  Studies have proven this method can decrease traffic congestion by as much as 40 percent, reduce the speed differential between lanes, and foster a sense of fairness that all lanes are moving at the same rate.

In January of this year, the CAA released its Canadian National Bottleneck Study  which found bottlenecks are the single biggest contributor to road delays, far outpacing traffic collisions, weather and construction. They affect Canadians in every major urban market, increasing commute times by as much as 50 per cent.



Vision Zero London, our road safety strategy, aims to reduce the number and severity of collisions occurring on our roads and increase road safety for cyclists, motorists and pedestrians alike.