Friday, August 21, 2015

Engineers say to ‘zip it’ when approaching work zones

It’s always interesting to see what kind of new “safe” road configurations road engineers come up with. Anytime we stumble onto a new one, the Land Line crew immediately wonders how our readers – the men and women who literally live their lives on the road – are going to react to some desk-generated idea.

We haven’t been surprised that traffic circles or roundabouts aren’t exactly popular. The diverging diamonds are confusing and have left more than one trucker scratching their heads wondering if it really is safer.

Earlier this week, a Missouri Department of Transportation newsletter winged its way into my inbox. In it was a reminder about the “zipper” merging concept that state DOTs are urging motorists to use when approaching lane closures.

Certainly not a new concept, but one that spurred a bit of discussion around here – especially in light of the recent lane closures that lasted the better part of a month just outside our windows here at Exit 24 on Interstate 70.

The “zipper” method is to use all lanes leading up to a lane closure, and to alternate merging vehicles at the pinch point. Engineers say it’s a safer, more efficient method than merging into the through lane at the earliest convenience.

Here’s a video about it by the Minnesota Department of Transportation.

All that said, we watched miles of trucks and cars backed up heading into the recent lane closure just east of the office here at OOIDA HQ. We saw tons (not all legal) of tactics used by drivers trying to get through the construction zone – early merging, shoulder driving, the touted zipper method, the “cut everyone off” method … you name it.

We also saw the trucks that formed the rolling roadblocks leading up to the lane closure, essentially forcing all vehicles to merge early.

All this raises the question: What is the safest way, in the eyes of the true professionals who drive these highways every day, to navigate lane closures? (Of course we’re talking legal methods.)

Just curious how you think this engineer-touted trick plays out in the real world.


  1. The zipper method DOES work; I saw it work in the ten years I lived in Germany. If we could get over our "Me first", "Can't get stuck behind a big truck" and all of our other attitudes about driving, it WOULD work....

  2. As in most things where more than one person is involved, it takes cooperation for it to work. Going too fast into a work zone, being in a hurry, thinking you are more important than the other drivers, all contribute to the zipper not working. Good concept, and in a world where there is a sense of community the zipper works. Personally, I will block the lane that merges so that the good lane can move freely without fighting the vehicles trying to race ahead and beat part of the line. When is my turn to merge there is always someone who lets me in. I hang in the lane until the last second so none else true to jump the line.

  3. I have driven 5 million miles over the road and it doesn't matter what idea they come up with you can not stop people from being idiots, they can't help it , it seems they are born with an idiot gene in their system.. You can not stop people from being in a hurry or being rude to others. You can however slow them down a bit. I-16 in GA. is in a constant state of repair, and they have accidents almost daily. It amazes me how these so called professional drivers can run off the road so often. That being said, yes drivers in cars cause some of the problems. The only real solution is to slow them down. We have 60 mph speed zone in the construction area. That is obviously too fast for many of the road warriors. I will tell them that they need to mark the sides of the roads better, at night and during the rain that left side is dim, put small, I emphasize the word (SMALL) rumble strips every 30 feet, just enough to wake them up and make them pay attention. Blue lights seem to scare people, the min. they see them they come to what seems like a screeching halt. Instead of the digital signs that show you that you are speeding in red, have not only that but a system where a Blue Cop light will come on, they will slow down even for a min would help. The way they angle their merge and exit ramps is terrible. Most of them are set up where you have to almost stop in the road to turn into the exit, the cones and barrels are set at such an angle that if you don't slow down you will hit them and that can cause them to roll into the traffic lane behind you. Getting back on and merging with traffic is not designed well, you almost have to do an Exorcist move with your head turning it completely around to see what is coming before you pull out into traffic, of course our trucks don't move as fast or pick up speed as fast as a car and it is obvious by the screeching tire marks on the pavement how many people have had near misses and wrecks because a truck driver pulled out with no acceleration lane.. yep designs and planning ahead actually knowing something about how trucks react and move and how much space they need to maneuver in would go a long way to making construction sites safer. I personally prefer the slow down and get over as soon as you possible can do so safely method , but then you are always going to have that one idiot that thinks they are more important than everyone else and will push the envelope to the danger zone in order to cut you off... Yep, you just can't fix STUPID. you can however slow it down.

  4. Well this is a sore subject for me and I would guess a lot of other truck drivers out there. Signs are up for traffic to merge now long before they reach the closure. The cars will drive 15 to 20 miles over the speed limit to make sure they are in the front of the line, driving on the shoulders and shoving others over to get back in the lane before they hit the cones. Training for how to merge in construction should be part of getting a license. Construction is a fact of life on the road. Until all segments of the driving population are properly trained things will likely stay the same.

  5. Jami, If followed by everyone, the zipper method works very well. I watched at a military installation one day as they emptied the base at the end of he day by having everyone use both lanes going out and using the zipper as they got to the main gate. They moved literally hundreds of cars out in minutes because everyone followed the rules and zoomed out at about 20-30 mph.

  6. About the only action I've seen that works is the Zipper method applied BEFORE the actual closure. Traffic starts filing into one lane between one mile and half a mile before the cones.
    As usual, a lane closure is not nuclear physics but the majority of the egocentric amateur drivers prioritize the number of cars they can pass over traffic flow. It never seems to occur or matter that traffic would flow much more smoothly if they would treat driving in such situations as what it is; a "team" activity.
    Drivers need to be careful using the rolling roadblocks. Many states have decided that we should not be helping ourselves and doing their jobs and have made rolling roadblocks illegal.

  7. It makes ZERO sense to force the travel lane to come to a complete STOP just to let the "me firsters" cut the line... if they are IN the travel lane well ahead of time, said lane KEEPS MOVING! This notion that "zipper merge" works ignores the fundamental reality of TWO lanes of STOPPED traffic as opposed to a SINGLE lane of MOVING traffic.


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