Moncton wants more drivers zipper merging this summer to reduce congestion

Most people have heard the term, but how many drivers actually do it?

The zipper merge is often promoted as a way to reduce traffic congestion when two lanes merge into one, but drivers who do it are often accused of cutting in or being rude.

The City of Moncton is trying to change that, using social media and billboards to spread information about the zipper merge and adding zipper-merge reminders to the flashing signs often seen in work zones. 

"There's a lot of people that think, for whatever reason, you know, I was here first, kind of, approach, so I'm not letting you merge," said René Lagacé, the city's director of engineering, who gave a zipper-merge presentation on Tuesday to council.

"Well, I guess the message is, for those motorists … that you're part of the problem, not the solution."

A zipper merge is encouraged when two lanes are merging, something that can happen on regular roadways but is often found in construction zones, when one lane is closed. 

The idea of a zipper merge is to use both lanes until the merge point, letting vehicles from each lane take turns, one after another, as traffic enters the single lane — creating look of a zipper from above. 

WATCH | See the zipper merge in action: 

Here’s how the zipper merge works — and reduces traffic

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Summer construction season is underway in New Brunswick, and in some scenarios, the zipper merge can shorten your commute. Here’s how it works.

But what often happens instead, Lagacé said, is that people will get into the same lane, forming a long lineup well before the actual merge point. Meanwhile, the lane next to it can be mostly empty.

"If you think about a lot of cars in a single line, let's say it backs up for a kilometre," he said. "Well, if you use both lanes, you divide that back up by two, right? It'd be 500 metres.

"That's really important, because the longer the backups, the more risk you have of blocking intersections or driveways or if you're on a highway system, that could lock some interchanges."

LISTEN | Moncton's push to make the zipper merge catch on:

Information Morning - Moncton9:40Are Moncton drivers ready to embrace the zipper merge?

René Lagacé is the director of engineering for the City of Moncton. 

As well, Lagacé said, a zipper merge works well to combat delays because of reaction time.

For example, he said, when vehicles are stuck at a red light, it can take a while to get going again when the light turns green because every car ahead takes a few seconds to react to the car in front when it moves.

The same thing happens when everyone piles into a single line ahead of a lane-reduction merge. But when two lines are moving simultaneously, the cars in the merging lane can slip into the natural gaps that form from reaction time, moving things along more quickly, he said.

The zipper merge is not new and is used in jurisdictions all over. In some places, drivers who don't allow others to zipper merge can be fined, Lagacé said.

New Brunswick is not at the point of introducing fines, said Lagacé, who believes education is key to teaching people that zipper merging isn't rude and isn't about anyone trying to jump the queue.

"If that lane sits empty, no one dares to go in there," he said. "If you can have, you know, 20 or 30, or eventually, 50 per cent of those people going to the other lane … we're working towards the zipper-merge solution."