Late Merge Studies Indicate It Is Faster and Safer
When you are driving on a highway and your lane is closing, do you merge as soon as you see the signs or do you wait until the last second to merge?
It turns out that this is a very contentious question with strong feelings attached. When I brought it up the last time on my blog over 2 years ago I found that while I believe that it is more efficient to merge at the last second (in a zipper fashion with each lane taking turns) close friends of mine had contempt for late merge behavior. Unfortunately for them, I did not find early-merge arguments convincing. While I completely understood that perception of late merge behavior was at the least, a black mark against it, I am one who has trouble letting go of a better solution just because other people are not convinced.
Yeah, these things stay on my mind for a long time.
The issue came up on Reddit today. it prompted me to read some responses and I was happy to see some of my same arguments used. But there were also references to scientific studies done, so I tried to look some of those up for you. Here's some info I encountered, for you to read or ignore at your pleasure:
Here is the Reddit thread where you can see people mentioning that late merging eases a backup by making more use of the roadway. It appears that in light traffic it doesn't matter when people merge, but in heavy traffic, late merging is better.
The rules in Germany are cited: "Heavy traffic rules: Whenever traffic is heavily congested, normal right-of-way rules go out the window and the "zipper rule" (Reißverschluß) goes into effect. This means that cars feed one at a time alternating from each direction, regardless of who has the posted right-of-way. The "zipper rule" also applies when one lane ends and merges into another. Each vehicle in the through lane must allow one vehicle from the truncated lane to merge in." (The zipper rule occurs at the point of forced merge.)
"When traffic is heavy and slow, it is actually much safer for motorists to remain in their current lane until the point where traffic can orderly take turns merging which is generally near the "MERGE" sign. Unfortunately, while the safer procedure is legal, it is not what has been taught."
Perhaps this will convince nobody and states will have to continue to think up ways to force people to merge at the last second. In the meantime, at least I've got science on my side while the early merge folks are cursing at me. But instead of cursing, why not consider just staying in your lane and merging at the last moment, like a zipper? I promise to alternate and let you in if you're next to me.
(I will be happy to browse any research that supports early merging. I would like to know the rationale behind any such research.)