How to Merge

Graphic from The New York Time Magazine

One of my great motivations for working from home is the ability to avoid traffic jams. I’ve coped daily with terrible traffic in the past, in Silicon Valley, Boston’s Route 128, and D.C.’s Beltway — commuting nightmares, all.

These days, I sometimes need to drive in and around Pittsburgh during rush hour, and the experience only reminds me how glad I am not to have to cope with such traumas on a daily basis.

Even traffic slowdowns aren’t so bad though. The emotional pain of traffic comes from having to merge — or more specifically, from having to merge with people who don’t merge the way you do. Depending on your point of view, the bad mergers either merge too soon or too late.

By nature, I’m a "get in line right away" driver. I studied a bit of queueing theory in grad school though, so I realize that everyone getting in line too early makes for an inefficient use of the roadway. Thus, I’ve trained myself to wait and get in line later, not at the very last moment but at least a bit close to the true merge point.

However, retaining those early-merge instincts as I do, I’m quite aware of how many people I’m pissing off as I cruise to where I intend to merge. I want to pull those people aside (or maybe contact them when they’re safely home and have cooled their tempers a bit) and explain that I have both queueing science and traffic laws on my side.

If you’re one of those early-mergers — or if you’re the type who skims along in an exit lane along a queue and then jumps into line at the last minute — take a look at this well-written article from today’s NYT Magazine: "The Urge to Merge" by Cynthia Gorney (herself an early-merger).

Most specifically, note how the perfect traffic merge would go:

FIRST, EVERYBODY REMAINS UNRUFFLED, without abrupt changes of lane or speed, as the lane-drop comes into view. Everybody takes three deep, cleansing breaths — all right, the experts didn’t say that, but they meant to — and considers both the imminent needs of everybody else and the system as a smoothly functioning whole.

Then everybody begins to slow, not too much, all in concert. All cars remain in their lanes, using all the real estate. (On the question of frontage roads and exit-only lanes, the experts waffled; those are arguably part of the real estate, they agreed, but they are meant for a different purpose, and this scenario relies upon everybody buying into the same rules. So no frontage-roading or fake-exit-laning, unless there’s a sign specifically instructing otherwise.) People in the narrowing left lanes refrain from shooting ahead, while people in the right through lanes — this is hard to swallow, for those of us inclined toward vigilantism, but crucial — leave big spaces in front of their cars for the merging that is about to commence. We resist the freeze-out-the-sidezoomer urge. We prepare to invite them in.

Finally, at clearly marked or somehow mutually agreed upon places, everybody starts conducting beautiful “zipper merges.” That’s the technical term — one-two, one-two or one-two-three, one-two-three — as indicated by the roadway configuration. The process has now worked at its ideal efficiency/equitability ratio: if all have behaved correctly, the tunnel passage has been both benign and, relatively speaking, quick.

Doesn’t that sound beautiful? Let’s all agree to adopt this style of driving and merging, shall we? C’mon, car-based world, we can do this!

6 replies on “How to Merge”

  1. The other day, I decided against picking up a check from a client in Shadyside because it was close to rush hour. Bear in mind that I would be driving from Bloomfield, a distance of 1.58 miles that according to MapQuest should take 4 minutes. I rarely choose public transportation anymore, but I still have an aversion to driving in traffic. I would die in L.A.

    Before I bought my first car a year and a half ago, a friend asked “what are you, a New Yorker?” Yes, a stubborn one with a bad temper who hates waiting. Maybe that’s all redundant.

    BTW, now that I’ve looked up my route on MapQuest for this comment, my frustration when driving that way will grow with every second past four minutes that it takes. And don’t get me started on the drivers who merge from the right-turn only lane on Liberty Avenue past the Bloomfield Bridge…

  2. I drive about once a month, thanks to my bus-pass payroll deduction plan and a very easy commute by bus to downtown, so I’m a little removed from the daily grind, as far as traffic goes.

    I do think, however, that the driving style of people depends on urgency. If you aren’t in a hurry, you’re more likely to be a courteous driver and merge early. If you’re feeling particularly magnanimous, you’ll allow other people to merge before you.

    If, on the other hand, you are running late for a client meeting in the south hills and you desperately need to get there as soon as possible, it’s understandable that you will probably be less concerned at the time about that guy behind you who is now riding your bumper because you cut in front of him at the last possible second.

    At least that’s how it worked for me when I was commuting 1 hour each way from Beaver Falls to Garfield. Spending that much time in traffic causes compassion for other drivers to dwindle fast.

  3. John: Based on your bad temper, I’m glad you don’t drive very often, and that when you do it’s not near me.

    Steve: The issue isn’t politeness though. Or rather, people may merge early to be polite or orderly or civilized, but ironically by doing so they make life worse for themselves and all the other drivers by using fewer lanes than are available, which effectively makes the backup longer.

    Late mergers, similarly, aren’t just being rude. They’re perhaps selfish in their minds (or perhaps not), but they make more effective use of the roadway.

    The big problem is people starting and stopping — that is, the speeding up and slowing down is what makes the traffic. If we would all slow down on the whole and especially in a high traffic situation, and if we’d not tailgate and not prevent others from merging, we would all sit in traffic less (and use less gas, by the way).

    I’ve seen simulations that make this really clear — can’t find any online that show the phenomenon I mean at the moment though.

  4. I find this fascinating. Honestly! In another lifetime I’d like to be an efficiency engineer. (One of my favorite movies growing up was Cheaper by the Dozen, where the military dad had all sorts of systems for operating a household of 12.) The image of the zipper merge sounds beautiful. I take a bit of “I knew it!” satisfaction at those drivers who merge too soon. In some cases there are big signs that instruct “Stay in lane until merge point” and still they get over. It falls under this irritant driving category I’ve named Over-Niceness. You know, those people who slam on their brakes to wave you in when there’s no one behind them for miles. Stop being nice! Just follow the rules and proceed in an orderly fashion and we’ll all get to our destinations.

  5. I moved to Montreal, Canada (metro pop: 3.5 million) from Toronto a few years ago and discovered zipper-merging is the norm in Montreal! It is indeed wondrous and fluid. There is not even any waving-in!

    Montreal drivers have a somewhat infamous reputation but I think that’s irritation from the anti-sharing driving culture of other jurisdictions. OK..there are a few quirks like having 15 cars change lanes…right before the lights on a four-lane artery. Then, I just slow down and watch the flawless ballet of near-collisions.

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