As discussed in this recent post from Arstechnica, if you merge early, you are bound to sit in the slow lane. If you're a Late Merger, sure, you'll zoom up the less-crowded left lane, but you'll probably endure the shade being thrown your way by the Early Mergers. They might even try to box you out when the two lanes finally meet.
So which are you, a Late or an Early Merger?
There is actually ONE correct way, which is faster and safer than the other.
Let me introduce to you the Zipper Merge, shown in this video from MnDOT. It's basically what would happen if we all became Late Mergers, creating the ever-perfect Zipper Merge.
I have long been a proponent of the Zipper Merge, which is a marketer's spin on the more negative term Late Merge. It is often seen as rude by the EMers (Early Mergers), because they think LMers are cutting in line. But if both travel lanes are filled in evenly and everyone takes turns, then it creates a clean zipper effect and both lanes will move forward at an equal pace.
EMers aren't doing anyone any favors. They are just creating a long line of slow traffic to sit in for themselves. If traffic is freely flowing, by all means EMers, merge as soon as your heart desires. But when it's stop-and-go traffic, the best practice is to all work together for a Zipper Merge.
In Pennsylvania in the 1990s, the Late Merge was introduced by traffic engineers after incidents of aggression at merge points. At the time, the most surprising result of this concept was it improved traffic flow by 15 percent.¹ Now, according to MnDOT, it can potentially improve traffic flow up to 50%!
Merging late may seem aggressive and selfish, but in fact, it benefits the group as a whole. It's those who are trying to be noble and polite - the EMers - that are creating a slow and frustrating traffic conga line much earlier than necessary. And now, we have the data to prove it!
¹Vanderbilt, Tom. Traffic:Why We Drive the Way We Do (and What It Says About Us). Alfred A. Knopf, 2008. Print.
Rightly or wrongly, Early Mergers generally look daggers at those who zoom up the Late Merger's lane and then try to jump into the line. I think it''s a sense of "Hey! I waited my turn in line; why can't you?" I've seen some road rage erupt at those check points where the two lanes intersect.
ReplyDeleteOn the positive side, I've seen most drivers in the open lane allow a single car in front of them from the lane being closed when traffic is forced to merge.
However, there's always one jerk who refuses to follow the merge courtesy of letting a car in line in front of them and will hug the rear bumper of the car in front of them so closely that I'm surprised that more rear-end collisions don't occur.
Next, can we discuss cars who poke along at 35mph on a two-lane highway when the speed limit is 55 and there's no traffic in front of them and the weather is perfect? They are oblivious to the long line of frustrated drivers trailing along behind them.