City of Windsor Encourages Zipper Merge to Keep Traffic Moving

Construction season is here, and the City of Windsor is encouraging drivers to embrace the zipper merge — a simple, effective technique that keeps traffic flowing and improves safety in construction zones and around lane closures.

Zipper merging occurs when drivers use both lanes fully until the merge point, then take turns moving into a single lane. When used correctly, traffic moves steadily instead of backing up in long single-lane queues. While many drivers believe merging early is more courteous, transportation experts say the opposite is true in heavy traffic. Early merging leaves valuable road space unused, creating longer delays and increased frustration for drivers. 

“The zipper merge works because it uses all available road space and encourages drivers to merge in an orderly, predictable way,” said Stacey McGuire, Executive Director of Operations and Deputy City Engineer. “It’s not about cutting in — it’s about keeping traffic moving efficiently.”

Key benefits of the zipper merge include:

• Maximizing use of available road space by keeping both lanes moving 
• Reducing traffic backups 
• Improving safety by minimizing sudden stops and risky lane changes 
• Promoting fairness by encouraging drivers to take turns at the merge point 

Motorists are reminded to stay alert in zipper merge zones and to be courteous to fellow drivers during the merging process.