What if I were to tell you that you could ease traffic congestion by 40%? It’s just one simple thing you have do. That’s it. One thing. But that one thing does come with a caveat. You will be considered by many people to be a douchebag.

It’s called “zipper merging” or more well known as "late merging", or to another extent "douchebaggery". If you are in a lane that is going to end, all you have to do is use as much of that lane as you safely can before merging. Since we’ve brought up this topic on the show this week, it’s become very obvious that there are people that just don’t want to hear it. It’s a douchebag move, done by horrible people who are only trying to screw over the patient people who got over early.

So I present to you, the following responses the typical "anti-zipper merging" arguments.

The "Everyone Passing In One Lane Through A Construction Merge Moves Faster" Argument

I've heard a lot of people say that it's the people who merge late that cause the bottle neck. Well, no. It's the two lanes moving to one that is technically the bottle neck because that will cause congestion and a slowing down of traffic regardless if there is anyone merging or not.

According to a study released by the Minnesota Department of Transportation, "Although motorists seem to believe that a single lane of traffic flowing into a work zone should flow through unrestricted and much faster without a slow down for merging traffic, this just does not happen in the real world of traffic hazards. Motorists slow down because of the uncertainty of the drivers’ actions ahead, poor visibility beyond, signs/drums/barricades and concrete barriers, unexpected temporary curves, construction equipment, and workers nearby. That slows down the rest of the line of traffic and the longer the queue (line of traffic) the more it slows down and a longer time before it regains speed. When traffic is heavy, a perfect line of drivers cruising through the work zone at safe highway speeds and spacing with no delay, is impossible to maintain."

The "It's Illegal To Merge Late" Argument

I had a message relayed to me that a police officer had said they would ticket me if I used the zipper merge, or merged late. I found this interesting because I've never once said do anything illegal or drive unsafely. In fact, driving safely should always be your number one priority when you get behind the wheel.

I have said to utilize the open lane, even if it's ending, as much as you can. And by "as much as you can" I mean to the point you can safely merge over. Don't anchor it over in front of someone, don't cut anyone off. Use the lane that is provided, and merge safely. Here in the United States, if you are in the lane that is ending, you are required to yield to the traffic in the lane that is continuing.

However, a country whose traffic conditions are considered to be vastly superior to ours, does have a law about late merging vs early merging. In Germany, you can be penalized for not using the late merge method. The same goes for Austria and Belgium.

The "Other Countries Aren't the U.S." and the "The Zipper Method Only Works With Robots Driving" Argument

I've heard both of these used frequently and yes, there is a response to these. There have been a few studies done. For instance, one by the Department of Civil Engineering at the University of Nebraska and one by the Minnesota Department of Transportation that was linked to above. Just in case you don't want to scroll up, here's another link.

These studies were done right here in the United States, with real people driving, in real world conditions. You can see more of the benefits by going to the links (sorry the Nebraska one is a full 122 page report). But the one main benefit of zipper merging that sticks out is from the Minnesota study that states, "We reduce the overall length of the backup by up to 50% (40% is common). While this may not be important in rural areas, it is critical in the metro area where the backups affect other interchanges. Therefore, we reduce the congestion problem for the other interchanges."

Remember that 40% I mentioned in the opening line? There you go. Just by staying in that lane, and merging safely at the end, you are actively helping ease traffic congestion.

And just in case you were wondering where MDOT was getting their numbers. The Minnesota Department of Transportation has added sensors to key roads; when they recognize pile-ups and congestions, electronic signs turn on and tell drivers to fill both lanes and merge at a later point.

The "You're A Douchebag" Argument

This is the argument I've heard the most. I get the feelings behind this. Getting over early and seeing someone move past you makes you feel slighted. Like you're being cheated out of your place in line.

But Leon James, a professor at the University of Hawaii who teaches a course about driving psychology says, “It’s so wasteful,” when talking about early merging. James also argues that the early-merge system is more psychologically taxing because it forces drivers to hope that they’re let in by others; they might not be. The zipper rule, meanwhile, simply dictates everyone yield at the end.

Plus, "There can be a weird idea going through people's heads of, like, 'Oh, these people are cheating, cutting in line!'" Washington State Department of Transportation representative Travis Phelps said to public radio station KUOW. "Well, it actually lets traffic flow if you can let folks in. Play nice. Treat traffic like a team sport. You gotta play the assist role. It's gonna help lessen the backups."

So I guess if you still consider using the zipper merge as a douchebag move, then I guess I'm a douchebag. But I'm a douchebag that is actively trying to help traffic congestion. I'm not using the other lane to get an advantage. I'm not looking to make you late to your meeting, or dinner, or wherever you are going. The simple truth is, it's being proven time and time again that using the closing lane as much as possible reduces traffic and I'd rather be a part of the solution, not the problem.

So take out what we're talking about and just think of it like this. If you can help reduce traffic by 40% by doing something simple, but refuse to do it out of principle. Who's really the douchebag?

Here are some videos about zipper merging just in case you wanted some.