Why is zipper merging (when a lane ends) better?


Why is zipper merging (when a lane ends) better?

In: Engineering

It’s effective for the same reason stop signs are effective – and by that I mean it’s effective only when EVERYONE does it. If everyone knows to let one go on one side, then one on the other side, repeat, it all works efficiently and quickly. But the problem is that everyone is kinda doing their own thing – and when some people are merging “properly”, some people are randomly holding back to let others in that have no business merging in at that moment, and some people are trying to jam themselves in way back at the start of the merge, it all falls into chaos. Zipper merging isn’t MUCH better than other methods, but it is a proven effective method when done properly. We just lack an effective way to get everyone on the same page, and unless everyone is doing it the same way, no matter what that way is, it will always be chaos.

It is absolutely the best way to deal with traffic. Traffic during congested times can be measured with physics similar to fluid dynamics. Think about a pipe. The place where the pipe gets narrower causes greater pressure, and in turn, slower flow. The sooner you make that narrowing, the earlier the traffic slowing occurs. Therefore, utilizing all lanes for as long as possible creates the best traffic flow.

Because nobody needs to stop. Its the same reason a roundabout is more efficient than a four-way stop sign. If nobody zippers, then one lane ends up having to completely stop and wait for someone in the other lane to let them in. In a zipper, everyone slows down a little but keeps moving.