Friday, August 26, 2016

The Zipper Merge might speed traffic, but do you dare?

Traffic brakes hard as a would-be "zipper" waits too long to make his merge.
Tired of traffic? Me too. So I am frankly amused by the latest highway improvement scheme I've heard of: the "zipper merge."

It's being promoted in U.S. states where winter weather means nearly all road construction must be concentrated in the busy summer travel months. Construction means lots of lane closures, where traffic is forced into single file for miles on end.

We don't have winter weather woes in Florida. Even so, there's plenty of road construction.

And, if you think about it, there are fewer lanes at every freeway interchange, as the "merge" lane peters out and a line of fresh cars squeezes onto the through lanes.

Traffic engineers are now urging drivers to stay in the disappearing lanes until the very last moment, cutting over onto the through lanes only when they've run out of pavement (or come up against the final road construction barrier).

Once the driver reaches the point of having to merge or crash, he's supposed to "take turns" with the through traffic, proceeding one after another on the main route, without slowing down.

Think of "One from Column A" then "One from Column B."

Or think of the teeth of a zipper coming together as you pull it up. Smooth!

Engineers say that, on a two-lane road merging into a one-lane they can get 40 per cent more cars through using this zipper technique.

There is only one problem: road rage.

The traffic officials try to cast this as a problem of merging drivers slowing to try to enter traffic when there's plenty of empty lane still in front of them. They suggest that drivers are thinking it would just be impolite to sneak ahead of cars already on the through road.

My guess is that these "too polite" drivers suspect they'd better merge early — or face the consequences.

This is because drivers in the creeping traffic on the main line get angry as they watch the Johnny-Come-Latelys in the merge lane zipping ahead, passing a hundred or more cars at one jump.

Then, at the last moment you either have to let them in or risk triggering a crash. Pushy bastards!

Once, zipping up a merge lane myself, a fellow in a big pick-up truck pulled sideways across the lane in front of me to defend his place in line. I've seen this happen several times to others and I've never been sure whose side is right.

Now traffic officials in Midwestern states are posting videos trying to educate the public that it is not impolite to race ahead of cars stuck in the through lane — it's actually a technique that helps everybody.

I don't disagree. But I do smile at the idea that improving traffic flow could be a matter of changing human behavior.

It might be easier to change the concrete than to change minds.

Bottom line: there's too much traffic. Using the merge lanes as, in effect, traffic lanes, does make space for a small number of additional vehicles, true.

I suspect the only real improvement will come when more businesses realize it's silly to have employees drive to work to sit at computers all day when these same people could work from home at less cost to the firm.

The quickest, safest commute is one that doesn't happen at all.

1 comment:

  1. Same happens here in the UK, David. Road users are not getting the obvious (safe and polite) message of "after you, Claude". Your penultimate para just about sums it all up!


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