That's why when I drive, I only wave one finger. It's less disruptive.

I believe this was mentioned in "Mission Impossible 3." Ethan Hunt's cover is that he works at the Department of Transportation studying traffic patterns. Early in the movie, where he and his wife are hosting a party at their house, you see Ethan (Tom Cruise) explaining the above mentioned cause of traffic to some of his party guests.

I've thought about while sitting in traffic ever since. Also, although it did wores at the box office, I thought that "Mission Impossible 3" was much much much better than the comically bad "Mission Impossible 2".

@SwatLax: blah blah blah...edit button!

This phenomena adds at least 27 minutes to my daily commute in Atlanta.

*clinto considers buying an ultralight and starts surfing EAA's website*

I remember reading long ago that it was the fault of all the unnecessary lane-changers that really add to the cram. If we all avoided that urge to pop into the next lane in congesttion to get just a few car lengths ahead (which never lasts anyway) we'd all move along at a faster clip.

Way to find the oldest photo of a traffic jam on record!

Um, they needed a team of scientists to confirm common sense?

@SwatLax:

I never saw Mission Impossible 3 because Mission Impossible 2 was when I decided I'd had enough of watching directors fellate Tom Cruise.

@muffinapocalypse: I have a team of scientists studying the effects of pork rinds on my relative body fat

My dad told me about this 15 or 20 years ago. He said you could figure out how close you were to the end of the jam by the decreasing frequency of the waves.

@LTDScott: Au contraire.

[www.railroad.net]

@LTDScott:
@PeteJayhawk:
Older! [www.geocities.com]
[content.cdlib.org]
[www.holmeonspaldingmoor.co.uk]

Shoot, they needed to do a study? This is so obvious.

The solution is obvious, too: keep more space between the cars. As soon as I start to see taillights flash even several cars ahead of me, I'm backing off the gas to open more gap.

The peaky speed change gets absorbed by the big space between me and the guy in front of me, while a longer, shallower wave gets transferred to traffic behind me. If several consecutive cars would all maintain a long gap, we could eliminate most of the waves entirely.

Personally, I blame it on the jackasses driving automatics. As soon as they start down any hill, the lack of engine braking causes them to step on their brakes, causing a brake-light chain reaction leading to...traffic!

There are also the idiots that step on the brakes for no real reason, other than they're talking on their cell and feel the need to slow down because somehow that allows them to continue driving while concentrating on their conversation. At least that's how it works here in California.

@TechnoDestructo: That means you missed "Collateral" with Jamie Foxx. You've gotta make an exception for that.

I went as Vincent, the hit man in the film for Halloween a couple years ago. And basically that meant I wore a grey suit, white shirt, and carried a nerf gun.

"When a jackass in a Miata (at least here in Dallas that is the most common occurrence)"

That's funny, here in SoCal it's most often a soccer mom on a cell phone in the biggest Yukon sold.

I heart Jalopnik and all, but really, the last 7 or 8 stories (or are they posts?) are really ho hum. I mean, Traffic Studies... Electric Bus... AAA Travel Predictions... PC from a Porsche Wheel (ok, mildly interesting there)... 100 car Transformers Logo... and an Indian Musical Montage.... all are pretty lame. Has the Gawker Christmas Party started already?

@UDMAN: Your comment is not any better. Stop whining.

@slackinfux: Word. The only reason for the huge slowdown in a local canyon is that people overreact to the freeway turning and going down hill at the same time.

i agree with the wave theory. always thought that, but i think the reason the wave starts is because of people merging on to the highway. traffic is always worse at parts of the highway that have more onramps close together. slow drivers should get up to the highway speed when getting on. if not then the people on the highway are forced to slow down resulting in the wave. plus the more cars there are the worse it's going to get.

@UDMAN: It's our job, as certified commentators, to pick up the slack and make this stuff interesting.

Personally, I'm not up to the task today (the streak continues!). How about you?

Around here it usually happens at the top of a hill, no matter the road classification. Even on interstates, brake lights suddenly appear as if they are afraid the road ends on the other side. Bless their hearts, sometimes I wish it did.

@goatrope: I've tried all day. But to no avail.

I always thought of traffic like a giant flywheel. If it loses its momentum, it'll take it the rest of the day to gain it back.

Traffic makes my 39-mile daily commute from Denton to Dallas take over an hour (in each direction). Sometimes 2hrs if there's a significant wreck along the way.

Bullcrap, it's not the fault of others around you. Each of us can get caught in it, each of us can do a little bit to help mitigate it. If drivers looked up past their own noses, they could work the distance to the next car up to minimize - and sometimes eliminate - their time on the brakes. And moreso for each successive car in the line.

If, on the other hand, folks come to a stop and fall asleep there, the delay grows. And they call it inevitable.

@ SWATLAX : I walked out of Collateral. What a lame PoS.

Concerning this theory: I actually had no idea this was the cause of it. This theory is new to me, so I'm glad that Jalop posted it.

I agree with dontforget on this one. It seems many of the people here can't get on the highway at any speed over 35 mph. So some nice person brakes to let them on the highway and the traffic jam begins.

and they discovered this now??? In Holland they started around 10 years ago with variable speed limits on the freeways in order to prevent this "wave".
In Holland they also started around 15 years ago with "car weaving" indications on the free ways.. because they realized that when people have to go from 3 lanes into 2 lanes the traffic slows down very fast because people don't change "weave in" with the remaining lanes at the right moment, but rather at the last moment, creating stand stills.

And the tapping of the brakes is caused by: Tada! People not paying attention! If people merged at the flow of traffic (which would require you to look at the flow of traffic, which means paying attention) nobody would have to hit their brakes. It's so irritating watching people pull onto the freeway. Right at the end of the ramp, OH MY GOD THERE'S A CAR, then they slam on their brakes and the car they pull in front of has to slam on his brakes, and thus starts the wave. Cops need to start giving tickets for people merging too slowly or driving below a safe speed or impeding traffic or something.

This is why all cars ought to be equipped with autopilot, with a master control system keeping everyone on the freeways spaced evenly, opening gaps for incoming vehicles, speeding things up when necessary and possible, etc... Think of the missed sleep you can catch up on during your daily commute!

I remember this sort of thing was mentioned in iRobot; Will Smith's character got slapped by his boss over a report that he'd been driving with autopilot turned off again.

I'm pretty sure they're caused by the a-holes who drive in the left lane at the same speed as the car next to them.

I was stuck behind some crazy lady paralleling the car next to her on a two lane highway once. Doing 55 in a 65... 1 minute passes, I flash my brights. 2 minutes pass, I flash my brights a little more. 2.5 minutes pass, I tap the horn and flash. 3 minutes pass, I lean on the horn. Fortunately I do not keep a gun in my car (hey Florida!) for if I had shots would've been fired. Strangely the person next to her did not speed up or slow down, this went on for some time as a line of cars built up behind me. After a minute straight of leaning on the horn she finally slowed and moved over. Then actually looked at me like I was the crazy one.

Nothing new to the geek set. Kind of like why buses show up in 3's.

I saw a program about this on PBS about 10-12 years ago.

So, this news still allows me to focus my traffic anger at some unseen goofbag somewhere up the road. As late as this morning said fool was imaginary, now I have scientific proof that they are real.

Hooray science.

This is VERY old news; I live in L.A. -- we know highway congestion, we practically invented it (right after we invented freeways...)

P.S. to Travis -- "When a jackass in a Miata (at least here in Dallas that is the most common occurrence) quickly enters the freeway"

Oh, sure, lay all the blame on us gay men...!

@Charles_Barrett: L.A. invented the freeway? The word was cloned in NY, Germany and Italy had freeways before L.A.
The Autostrada dei laghi is considered the first freeway in the world, build in 1925.
Another misconception about L.A. is the traffic... while there is a lot of it, the jams are absolutely nothing compared to the traffic jams in Europe, especially he ones in the Netherlands, but also the ones around all mayor cities in Europe, except maybe Berlin.

@sos10: even Canada had freeways years before L.A. got their first freeway (Pasadena Freeway 1940)

I'm sure we all agree that all the world's traffic problems are always caused by the *other* drivers on the road :)

@slackinfux: Wait... automatics where you live have only one gear? Going down a hill in the Buick I used to drive, I'd just shift from (D) which I think was their way of saying Overdrive to D. or 4 to 3, or 7 to 6 if you're in a Mercedes. You can still downshift in an Automatic... people just don't seem to know it.

I'll have to look into this "traffic" thing they're talking about. Where I live, it's all winding mountain passes with nary a car (or, for the record, a highway patrolman, thanks to RCMP budget cuts) to be seen. Ah, bliss.

Hah! I'll trump all you people :)

Many of these problems were solved years ago.

Futurama

Futurama was an exhibit wherein a highway system was developed (from scratch) and shown. Now, at the time there was no interstate or the like so there was no model to go on. GM went to a guy called Bel Geddes (a name that is maybe familiar) and said "please build a road system that makes sense".

You might imagine he fumbled it and we're living with his mistakes, but no. He wanted to get it right, so he researched the various problems associated with that sort of thing--including traffic problems--and then very carefully designed a system whereby those troubles would be minimized or eliminated. Since we're talking about how onramps cause traffic jams, check out his onramp/offramp solution!

The resulting system was astonishing, and those who saw it knew they had to build it. The only problem is: they didn't realize there was more to it than building big roads. So they just did whatever came to mind. And we're living with those mistakes.

That sort of attitude is, if you ask me, part of the reason we haven't had a significant improvement in our road technology for the last... i don't know... how long? How many of us are still going 55 or 60? After how many years of technological advancement?

...

Sorry, i'll stop. I'll stop.

I was taught years ago that drivers tend to cluster --or clog up--in groups and hence one brake light begats the next. The trick is to try to run between the clusters. But I see this every day, most often caused by changing lanes and by poor merging. I also read that you should resist the impulse to touch your brakes by reflex when you see them ahead unless you really do have to slow down, to break that brake wave.

@Novaload: exactly, I do the same.. keep distance, avoid unnecessary braking, merging as early as possible.
And driving as fast as possible, when possible. :-)

What about those who drive autobox car with 2 feet; their brake lights come up every time they breath or fart... I hate them as they are very dangerous, but what can you do? Legal amputation of the left leg is not a popular solution, I think.

I covered the math that goes with this phenomenon a couple of years ago in an Operations Research course, but I would have to pull out my textbook again to look up what we called it. As pointed out above, the solution is to have everyone increase their following distance and pay attention to what's happening around them.

Then again, who wants to solve calculus problems on traffic patterns when you can just slam on your brakes on the freeway and see what happens?

Sir Brakes-A-Lot must die!

128 in massachussetts immediately comes to mind every time I hear words like "traffic jam for no reason." I heard a rig pass through with straight pipes around 3am. I was a punk kid on my bicycle near 128 must be 20 years ago... I almost went for a tough career.
The traffic jams bothered me that bad. Before I could drive.. I wanted No 9to5, no 8to4, no time clock nothing. 40 tons, 70mph, bellowing through a place all sleeping at the smae time. All millions of them....it is that bad. The only phenomona, is the man god that established our time and what and when to do with it.

@dolo54: Yeah it's them, and there sure are a disproportionately large number of the parallel drivers in FL.

@bdon: COTD it's like the smae as Joyce, or vomit of is the man god$.

@TechnoDestructo: Amen brother.

@dontforget: Ahh, California. Where people entering the freeway are doing 20 under the limit, then get pissed off that you are there and slam on their brakes as the guy next to you decides to merge into your lane.

@sos10: Of course there's nothing else in Canada to make going from nowhere to somewhere else exciting except maybe speed.

Ok, so I'll be the nerd "mathematician" who will say that traffic is governed by a nonlinear wave equation that has been well known for a long time. It's something like u_t+u_x*u=f(x). Anyway, u is the density of cars, and the underscores mean derivative with respect to. Still here? f(x) is just the forcing function (your friendly idiot swerving while merging, causing you to brake).

Anyway, the u_x*u term gives rise to shocks which propagate backwards through the system. The shock is your traffic slowdown.

@philibuster: Now I get it. Really, it makes more sense this way than just some a-hole in a Miata. Here in the Pacific Northwest, I think you can replac