The Right Way to Merge

A few days ago I wrote about late merging [2] and, not unexpectedly, got a lot of feedback. This is, after all, a universal experience. What amused me was the anger many of the early mergers feel toward the late mergers. Many people make this into a moral issue or a spiritual issue, as if God has offered us a “thus saith the Lord” when it comes to the ethics of merging. As Tom Vanderbilt says in the book Traffic, there seems to be a whole worldview contained in early merge or late merge strategies. The conventional merge, the situation we all find ourselves in every time we drive in traffic, “tosses the late mergers and the early mergers together in an unholy tempest of conflicting beliefs, expectations, and actions. Perhaps not surprisingly, it performs the worst of all.”

Having done the legwork and having consulted with the experts, here is Vanderbilt’s conclusion on how to best handle merging. I thought I would post it today just to tie up the loose end of that conversation.

The next time you find yourself on a congested four-land road and you see that a forced merge is coming, don’t panic. Do not stop, do not swerve into the other lane. Simply stay in your lane—if there is a lot of traffic, the distribution between both lanes should be more or less equal—all the way to the merge point. Those in the lane that is remaining open should allow one person from the lane to be closed in ahead of them, and then proceed (those doing the merging must take a similar turn). By working together, by abandoning our individual preferences and our distrust of others’ preferences, in favor of a simple set of objective rules, we can make things better for everyone.

So there you have it. Traffic will flow best if there is an even distribution of late mergers to early mergers and if everyone does their best to alternate. Just stay in the lane you are in until it makes most sense to come together. You need the late mergers and the early mergers to work together if you want traffic to flow with the fewest interruptions.