04-04-2025
The zipper merge explained and why you should use it in construction zones
Starting in early April, the New York State Department of Transportation began lane closures on the Interstate 490 bridges over the Erie Canal and Kreag Road. Drivers going through the work zone are asked to use a zipper lane to merge into the open lane.
The westbound on-ramp at Exit 27 will be shut down, and I-490 westbound will be reduced to a single lane during construction.
Beginning April 7, eastbound traffic on I-490 will also be narrowed to one lane, weather and scheduling permitting.
Drivers moving through the area will need to follow a late-merge 'zipper' pattern, alternating turns to enter the open lane smoothly and safely.
Here is some guidance from AAA on handling the zipper method as a driver:
A zipper merge operates like a zipper on a jacket. Drivers approaching the merge must perform a late merge, taking alternating turns—similar to how the teeth of a zipper come together.
Here's how it works: As you approach a lane closure in a construction zone on a crowded highway, resist the urge to merge early. Instead, stay in your lane until you reach the designated merge point. From there, drivers in both lanes should take turns merging—one by one—into the open lane, like the teeth of a zipper coming together. It's safer, smoother, and helps keep traffic moving.
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The zipper merge only works if drivers cooperate—taking turns and working together to keep traffic flowing. Maintaining a steady pace and avoiding last-minute braking helps keep everyone safer and traffic moving.
A zipper merge is the quickest, most efficient way to move traffic in a construction zone. A 2013 study conducted in Minnesota found that it can reduce traffic backup lengths by up to 40%.
When traffic flows at normal speeds with no significant slowdowns, merging early into the open lane is best before reaching the closure point.
But no matter the traffic conditions, the key to a smooth merge—early or zipper—is driver cooperation and steady, predictable behavior. While some see the zipper merge as aggressive or unfair, studies show it eases congestion and encourages a more balanced, respectful traffic flow.
Genae Shields is the business and development impact reporter working on mobility stories that dive into how people get around Rochester and its surrounding areas. As a member of the local community, Genae enjoys learning about newly emerging businesses and changes that impact Rochester's BIPOC and LGBTQ neighborhoods. She also enjoys supporting local artists and nonprofit organizations. Contact Genae at gshields@
This article originally appeared on Rochester Democrat and Chronicle: Zipper merge explained and why it should be used in construction zones
