HOWTO singlehandedly erase traffic jams by driving slow

Update: I've updated the link to Bill Beaty's original article -- the one I linked to originally was a scumbag plagiarist.

Jeffrey sez, "A fascinating article about what causes traffic jams, and how to drive differently to help ease 'stop and go' traffic. It is interesting to see how basic human instincts (or maybe just the way we have been taught how to drive) can turn a crowded road into one that is jammed with stop and go traffic. It is probable that self-driving cars will eliminate many of these issues before many humans have time to learn these techniques. However, it is very encouraging to hear the author's anecdote about how he was able to singlehandedly erase a traffic jam in his own lane:"

On a day when I immediately started hitting the usual "waves" of stopped traffic, I decided to drive slow. Rather than repeatedly rushing ahead with everyone else, only to come to a halt, I decided to try to drive at the average speed of the traffic. I let a huge gap open up ahead of me, and timed things so I was arriving at the next "stop-wave" just as the last red brake lights were turning off ahead of me. It certainly felt weird to have that huge empty space ahead of me, but I knew I was driving no slower than anyone else. Sometimes I hit it just right and never had to touch the brakes at all, but sometimes I was too fast or slow. There were many "waves" that evening, and this gave me many opportunities to improve my skill as I drove along.

I kept this up for maybe half an hour while approaching the city. Finally I happened to glance at my rearview mirror. There was an interesting sight.

It was dusk, the headlights were on, and I was going down a long hill to the bridges. I had a view of miles of highway behind me. In the other lane I could see maybe five of the traffic stop-waves. But in the lane behind me, for miles, TOTALLY UNIFORM DISTRIBUTION. I hadn't realized it, but by driving at the average speed, my car had been "eating" traffic waves. Everyone ahead of me was caught in the stop/go cycle, while everyone behind me was forced to go at a nice smooth 35MPH or so.

TRAFFIC WAVES (Thanks, Bill!)


  1. I’ve tried this, driving an even speed that is the mean of the fast/slow inch-worm traffic. And what happens to me is that people cut in front of me when the space opens up. Then I have to slow down more. And more people cut in front.

    1. It’s another one of those beautiful practices that relies on human kindness and rationale to succeed on any appreciable scale–so it is doomed to failure.

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        Traffic moves forward, jams move backward. The behaviour of the traffic
        (driving style, engine power, nonlineartities perhaps) should determine
        if they become worse or peter out with time. Maybe something for a
        computer simulation.

        1.  The EOD folks I worked with had vehicles which said on the back “DANGER–HIGH EXPLOSIVES Keep back 500 feet” No one tailgated or cut in front of them.

      2. And violating the rules of the road; slower traffic to the right, allow faster traffic to pass.

    2. Exactly the point I came to make. I can usually do it for short periods of time but soon the gap in front of me fills with people moving in from one of the other lane.

      Then after a bit people behind you decide you’re the slow down and purposefully go around you to fill that gap, then get stuck in the stop & go.

    3. Hahahaha! I guessed it! The first four words of the post

      “I live in Seattle”

      Let’s just say that what works in Seattle doesn’t work in Southern California or New York (or almost anywhere in the world). Seattle is special. If you use your turn signal and need to cross four lanes of traffic to make an offramp in a quarter of a mile in Seattle, you will make it.

      1. The funny thing about this is that there’s not much guessing to do. The dynamic speed zones on the 405 and 520 tell you what speed you should go to kill the waves, but they’re often ignored.

      2. Seriously? I live in Seattle and I have given up letting anyone in ever. Seattle drivers are all arseholes. If one person ever said thank you for being let in I’d start being courteous again, but as of now, they can all fuck off. 

      3.  Whoa.  What is that experience like?

        In Chicago, if you use your turn signal, drivers will speed up to cut you off.  Any tourists to Chicago, if you’re wondering why no one uses turn signals here: that’s why.

    4.  I’ve tried it on LA, Boulder, and Dallas highways, and it works fine.

      However, I did find many particular spots where it totally fails.   The road-psychology apparently varies widely with location in a city.  In some places nobody but a couple of psycho lane-weavers will bother to jump into spaces, but a few miles away nearly everyone does it.    So, if you see it working great, it means that you’re commuting on a highway …where it does work! :)  And if it utterly fails, just try it in many other spots.

      Or just watch the big trucks.   If they’re all able to maintain a forward space without it instantly being filled, then you’re on a “good” stretch of road.

      1.  This is my observation in Minneapolis too, some places and times it works, others it doesn’t.  But I think there is another option.  Those waves build up, I think, because overloaded roads with too-close following are brittle.  If roughly one out of 20 or 30 cars would allow a larger (but not as large as the OP suggests) following distance it would give the whole system elasticity, and only reduce the carrying capacity a small amount.  By brittle I mean: one person taps their breaks, the too close follower has to break, the next too close follower has to stomp their breaks, etc.  People do zoom around me, but since I am going slower than them it doesn’t matter to me.

        1. It’s really interesting that you mention “brittleness,” because as someone with a tiny bit of materials science background, I can’t help but view traffic as propagations of point and line defects through metals! I know humans are active agents, and atoms aren’t, but the similarities in the behavior and consequences are really interesting to me.

          I’m also a fellow Minneapolitan and have had the same experience. It even changes in the same places depending on the day of the workweek. I’d love to shadow a MnDOT traffic engineer for a day to get the inside scoop on all the awesome data they’ve probably got on this problem.

      1. Exactly, but it’s Prisoner’s Dilemma with an illusory prize everyone pursues, and a real prize which is ignored by all and thrown in the trash.

        Most drivers seem to think that they’ll get to work earlier if they can get ahead by a few cars.   Nope.   Heavy traffic is moving at about one car per second, or per 2sec.   So, to cut your trip time by just 5min under those conditions, you’d have to pass several hundred other cars.   Passing only a few cars is worthless (only a psychological prize.  Your trip isn’t significantly shorter.)

        Tailgating and lane-weaving doesn’t work.

        Or put more simply:   in our desperate attempts to gain seconds, we slow ourselves by tens of minutes.    Or:  group speed is everything, and our place in line is meaningless.

        Or:  to rapidly exit a burning building, should we all be constantly shoving against the person ahead, trying to jump the line, fighting with others?   Yeah right, good way to die in a fire.

        1. Group speed is everything? Sounds like SO-SHULL-ISM to me, commie. I’ll take my individual gains because this is Murrica.

          1. The only reason socialism doesn’t trump capitalism is because of short-sighted, self-interested people like you who cut the line.

          2. Wow. I really didn’t think my comment need sarcasm tags. I really thought it was that obvious.

            Everything in that comment was sarcasm. Nothing in this comment is, including this: I’m an anarcho-communist, not some stupid fucking cappy.

        2. This fails to take intersection tmings into account; an extra 10 sec. might mean not having to sit at a red light for 3-4 minutes. There’s no way to predict this, of course, but people remember the negative examples — where they didn’t cut off a handful of cars and ended up being stuck behind a slow car that made them late for work — much more than the positive cases where they were civil and still made the green light.

          1. Again:  the illusory gains aren’t real, they don’t get us to work earlier, and the effect with intersections doesn’t exist (it’s illusory.)   An extra 10sec *doesn’t* ever make us sit at a red light any more than it lets us narrowly avoid the red light.

            Of course none of this applies to city-grid driving.  In that case small delays really can knock you out of synch with the wave of green lights.  But I recall one study that showed that cities with extremely aggressive drivers had significantly better throughput.  So, competitive “race-driver mentality” may lube the flow down in cities, while at the same time it jams up those “gear teeth” on highways.

          2. Funny….I was thinking you didn’t have a clue about driving in a major city, and then you said:

            “Of course none of this applies to city-grid driving.”

            Yup.  Not all intersections are timed, but many (including the main ones) are, and it really can make a significant difference if you know how to work with that timing (or are stuck behind someone who doesn’t).

          3. Sunset Blvd in SF is timed. It’s quite entertaining to drive it, because you can drive the speed limit and go about five miles without stopping while watching drivers who don’t know the road floor it and screech to a halt at every intersection.

          4. The grid streets in Burbank, CA, seem designed to keep a person driving (or idling) in Burbank for as long as possible, and they can be really irritating for drivers who are used to the traffic-light patterns of the surrounding Greater L.A. area.  The one Burbank street that I can think of that works is westbound Victory Boulevard.  If you drive the prescribed 35 mph, you’ll hit every green light.  If you do anything else, you’ll hit reds every time.

        3. The phenomenon where individual decisions lead to a worse outcome for every participant is sometimes called the “price of anarchy”. I read a pretty good survey here:

          A good example: Sometimes, when you open a new highway to reduce congestion, you make everyone’s commute worse. (Without adding any new cars to the road.)

    5. Exactly! Leaving any more than a car length of space between you and the next car is just an invitation for all manner of vehicles to cut in front of you. With this technique, you would have to continually slow down to maintain the gap. It will also make the people behind you hate you with a deep intensity.

    6. If I do this in Boston, I get passed not only from people in the lane next to me wanting to get 2 spaces ahead, but from people behind me who swerve through the breakdown lane.

      1. And you’re all going the wrong way on a one-way street!

        There’s a reason that I didn’t get a license until I left Massachusetts.

    7.  People do cut in front, but at least in my area it still works pretty well.

      I have often thought that with a phone app that knew the timing of the traffic lights it could tell everyone exactly how fast to go to avoid any stopping at all. Even if only %50 of people used it, it would probably be enough to change the whole traffic flow.

    8.  I think this was kind of the intention, as I recall the original article.

      Still, you’re pointing out the real shortcoming of practices like this: YOU CAN ENDANGER YOURSELF AND OTHERS.  If you drive in a way that encourages people to get angry, tailgate, or undertake illegal measures to get around you, you’re adding to the problem, not solving it.   You can’t apply this mindlessly, and if you’re driving in a pack of self-indulgent jerks, don’t do it. 

      Still, this method can work if enough people apply it.  Notably, in the early 90s in LA (after the first major road rage shootings), people spontaneously did this out of courtesy, resulting in slow-moving traffic rather than jams.  I was in some of them, and while they were spooky, they worked.  The problem was, it only took one jerk trying to weave in and out of this slow moving pack to transform traffic into pure stop-and-go.  Nowadays, the ubiquity of cell phones seems to have transformed angeleno drivers back into self-indulgent jerks, and it’s rare to see the mass movements of 20 years ago.

      Incidentally, tell-tale signs of the self-indulgent jerk traffic include a high proportion of BMWs, Audis,
      and SUVs in your immediate vicinity.  Teenagers are also a huge problem (no surprise there).

       From experience, I’d also advise against doing this
      near military bases, where a proportion of the drivers evidently still
      think they’re in Basra or Baghdad and that weird drivers are all wearing suicide vests. 
      They freak out if  they can’t get free on their own terms, and that’s
      not a good place for civilian bystanders to be trying to even out the traffic flow or hypermile.  Fortunately,
      this is becoming less common.

    9. So they do, but they don’t stay there. As soon as they perceive that a neighboring lane is moving faster they will jump into that lane, and your ‘hole’ resumes. You can drive in a manner to anticipate this. 

    10. That always happens.  You get people who cut in front of you and you might as well just speed up and stop.

  2. Yup. Traffic moves forward, jams move backward. The behaviour of the traffic (driving style, engine power, nonlineartities perhaps) should determine if they become worse or peter out with time. Maybe something for a computer simulation.

  3. They tried to force that here in Seattle with a multi-million dollar prediction system that adjusts the speed limit based on traffic load.  There are signs over each lane, maybe every half a mile, through the busy part south of downtown and out on I-90.  Instinct and habit prevents it from working though. Everyone just jams themselves up on the bumper of the person in front of them just like they always have.
    A lower-tech version of it: I forget where it was that I saw it, maybe Baltimore? But they had painted big dots on the road, spaced out so that if you couldn’t see 2-3 of them, you knew you were too close.  Again, ignored. (also, only applies to one speed?)
    Gotta go back further maybe?  Drivers ed?  Shock collars hooked to our ignitions?

    1. Intelligent car-trains, with magnets “locking” cars at specific distance. I believe it’s part of the strategy for Google’s self-driving cars, but it could probably work on its own, if manufacturers and legislators established a common standard for all vehicles.

      1. That is Volvo’s initiative. I believe Google plans to have all the cars be fully autonomous and just communicate with others nearby wirelessly.

  4. I’ve done this before too.  Yes, sometimes other cars will fill up the empty space but I’ve found that the only benefit is not having to brake as often.  Unless you can get everyone driving faster (on average), then this won’t make a difference.

    People will always slow down to look at a wreck on the opposite side, it appears to be a human nature which you can always count on.

  5. This made me smile…I’ve been playing what I call “the Traffic Game” for years. Best score is achieved by keeping a steady speed; the harder you have to brake, the more points you lose. Watching other car’s “body language” and carefully balancing the size of your gap helps minimize cut-ins…though you can’t eliminate them, there are always some a**holes. But now I know I can also track my score by glancing in the rearview mirror–thanks!

    1. I am so glad you mentioned that!  When I was commuting on the 101 in Phoenix/Scottsdale I did *exactly* the same thing–start at zero points, and every time you hit the brakes you lose a point.  The only way to win is to stay at zero.  Many, many close scores, but only two perfect scores :)  This was also in a manual, which makes engine braking to control speed much easier.

    2. I find rather than looking at the car in front of me, I concentrate on keeping a roughly constant distance from a vehicle quite a way in front of me.
      This seems to work a lot better in the UK, I rarely have someone cutting in front of me.

  6. My high school band director used this traffic effect as a metaphor to teach the band how not to fall apart. He would note the “accordion”  effect of bad traffic as being caused by people rushing to fill in the space ahead of them and then having to wait. He told us that if the bass instruments rushed, then the higher instruments would hurry to catch up and would be going too fast when the bass instruments realized they needed to slow down and an aural mess would ensue. His solution was the same as the one here: everyone should keep their eyes on his directing and  go the same pace and we’d all be fine.

    1. Ah, band marching. Is there anything more fulling then musical cadence. If there is, I don’t want too know. 

  7. This is a pretty well-modeled phenomenon. As some of the commenters have indicated, individual self-serving driver behavior is the weak link to fixing this. Removing driver control is the easiest way to fix this. Anyways, welcome to the world of Civil Engineering and Traffic Engineering.

    1.  Oh, and I forgot to mention that all this stop-and-go action really wrecks your gas mileage, brake pads, and other car parts.

      1. Yeah, hyper milers use this trick to increase mpg, and the anxiety level of the other drivers.

  8. As someone who drives a manual the other 95% of drivers on the road can suck it.  I’m not riding the clutch all day…I’ll be in a gear and cruising at that speed, cut in front of me and we are just going to go slower.

  9. Anyone else witnessed  this on a highway done by a pair of semi drivers, side by side; occasionally a single trucker straddling both lanes? Just ruling the issue, with a tenth of a mile of  empty road in front of them; behind, everyone moving at a steady 5-10 mph.

    1.  Police do that in Belgium & Netherlands; using pace-cars to forcibly smooth the traffic during the massive vacation exodus.  Called “Blokrijden”

      Then there’s this:

      (illegal 55mph pace cars!)

    2. It’s a LOT of work shifting up & down in a semi, and it runs up the gas bill.  Even apart from the tandem strategy, they avoid it like the plague.  In B2B traffic the semi is the one to follow, if you want an easy ride.  

    3. In Europe, that happens at 56 mph and is called “elephant racing”. Basically, big trucks have to have 90 km/h (56mph) speed governors fitted. Some tolerance is allowed as to what these governors are actually set to, as they can’t be perfectly accurate. The drivers prefer to just let the governor control their speed for them.
      The problem happens when Truck A with its governor set at 56.1 mph comes up behind Truck B with its governor set to 55.9 mph. The driver of Truck A doesn’t want to make the effort of staying behind Truck B, so tries to pass- but with a speed differential of only 0.2 mph, that pass will take a long time.

      If the driver of Truck B is sensible, he will take his foot off the gas for a bit and let the faster truck by- but often, this doesn’t happen and the road ends up being blocked. As big trucks usually drive when the roads would otherwise be fairly empty, this slows down the car drivers behind.

      Special bonus is when just as Truck A is about to complete the pass, they come to a steep hill. Truck A is more heavily loaded and/or less powerful than Truck B, so drops back- and has to start the whole overtaking thing again…

  10. Something else I’ve never understood is how… let me phrase this correctly:

    there’s two lanes per direction on a highway, traffic speed is 60 mph. 
    Up ahead, one lane is closed, I would suppose that speed should go down
    to 30 mph with no problems, but NO, it goes down to a herky-jerky 5
    And the same thing happens when there’s 4 or 5 lanes per
    direction, even when the lane closed is the far-right one.  Like a
    constant series of individual irrational decisions, bee swarms behave
    better than we do behind the wheel.

    1. The cars are too closely spaced and can only cut in at the end of the line. People think they’re punishing the merging lane for not planning ahead, but they are the ones who are having the greatest effect on slowing everyone down. As the article ( says:

      To ease this type of jam:

      Maintain a large space ahead of your car.
      Never “punish” late-merging drivers by closing your gap. It’s illegal, and for good reason.
      Encourage one, two even three cars to merge ahead of you.
      As you approach the final merge point, open your space wider and wider.
      If traffic slows to a complete stop, KEEP TWO CAR-LENGTHS OF SPACE OPEN AHEAD OF YOU.
      Fed Hwy Admin says: merge at the last minute. Early merging is the cause of jams.
      MnDOT: Do The Zipper Merge
      MnDOT vid on proper merging
      Other suggestions:

  11. Most drivers seem too think, if the way is clear, hit the gas. Even if it only means gaining a few feet in traffic. There are weekend’s end highlight tailgaters who keep on  the forwards vehicles rear till they are granted allowance too move forward and annoy the next driver in front of them. The list type goes on…

    Seems if more lead foots where conscientious there would be less animosity. In a perfect world and such….

    Answer, stop driving and take alternative transport. Or drive less and incorporate other means of travel.  

    A WoodyWood Pecker cartoon shows this fast vs slow approach too traffic. Its out there some were.

    1.  If you can even out a traffic wave you’ll reduce emissions more in that trip then a month of alternative transportation.

      Because you are increasing gas mileage by at least double for everyone on the road…. not to mention wear and tear on brake pads and nerves.

  12. I drive like this a lot, perhaps because I have a 1958 Chevy with a lot of mass and ancient brake technology. Hmmm… get everyone to drive old land-yachts?

  13. It’s clear he doesn’t live where I live. Steady speed… I just don’t use the highway anymore. It’s going to take 2 hours anyway so I might as well spend that going 30 mph through residential neighborhoods instead of parked for 20 minutes then moving at 15 mph, then parked for 20 min… and so on.

    That being said all this just triggered my highway pet peeve. People who will not let you into the exit only lane because they are too busy trying to cut, like five cars ahead, in traffic just so they can sit there. Stupid. 

    Also people who will not merge in front of your car because they are determined somehow they can get a car or two ahead… only to end up behind you, frothing about it for the next 15 min because it isn’t like anyone is going anywhere after all.

  14. Nice that they plagiarized my website with no back links to the original.   (That way nobody can see the current version, or the FAQ, or links page, or comments, etc.)

    PLEASE read the trafficwaves FAQ before commenting.   It might also help to read the  current version rather than one that looks to be ten years old.

  15. This doesn’t work.

    I do the same thing, for the same reasons, and it has a marked impact on the cars most immediate to me in my lane – but it does NOT affect cars way behind me in my lane.

    What Jeffrey observed may have been possible if the lanes were restricted, but if people can change lanes, then you can’t have such an impact on your lane. This is because it doesn’t take long for smooth traffic to “ripple” due to lane changers (not to mention distracted drivers who find themselves slamming on the brakes  when they’re surprised to see a bumper in their face).

    This is because even as I’m “eating the traffic waves” in front of me, new waves are quickly forming behind me. The ripple effect is hard to stop! Here’s why:

    For normal non-traffic-wave-eating drivers, when a car enters your lane in front of you, you have to tap on the brakes to account for the loss of space. The car behind you then has to tap on the brakes a little bit harder, and the next car presses the brakes harder still. Before you know it your lane is at a standstill, suddenly people abandon the lane en masse, and lots of space opens up. Traffic rushes to fill that space, achieving relatively artificial speeds that bring them quickly up to meet another “wave” at a standstill.

    So because this ripple effect occurs so quickly, even if you are smoothing out your local lane traffic, the cars behind them are busy causing “ripple” effects that undermine your efforts.

    Sitting it traffic means that you have too much goddamn time to think about this, so I can elaborate with another example, where Jeffrey’s technique did not impact traffic en masse:

    Any Canadian driver has been stuck behind the plows during the winter. The plows intentionally block all the lanes to prevent risky drivers from trying to pass them.

    This line of plows typically goes exactly 40km/h. The traffic immediately behind them is completely moderated to this speed; you don’t see any of the stop-and-go-waves. But half a kilometer further down the road the traffic will have managed to create stop-and-go ripples, and not far behind them people will be at a standstill.

    So really, the wave-eating technique would only solve the problem if everyone did it… and there you have it; once again traffic jams are caused by collective human behaviour. Not much you can do about that right?

    Part of the reason I think that driving frustrates people so much, and why we can’t solve simple problems like this, is because unlike foot traffic, automotive traffic has very little in the way of communication. Besides flashing your lights and giving the finger, nobody can communicate much. If we figured out a way to add facial expressions to cars, I bet most of these problems would go away organically… FaceCars… shit, google’s not gonna like that.

    1. No, not everyone has to do it.    A similar experiment has been made (using dynamic cruise control,)  and apparently it only requires a few percent of drivers.

      To find research papers, search on “synchronized flow.” That’s the term describing the smoothed, wave-free traffic state.

      1. That is a nicer postulate, for which deviation can be blamed on the differential in views from say, lane to lane or merging modes. Nicer than forcing both oscillation and piecewise corrections where lossy, but less nice than pulling over with 3 sufficient gadgets (tennis ball, book, raquet; PSP, Zune2, Unity11) and having a nice run on those while golden hour or krunked traffic passes. Not to say you cannot average 40MPH doing that on a bus or something.

        So, did you have a particular playlist? Spektrmodule 25? If you are doing 35 I am absolutely for tap-sharing…

  16. seattle.    hippies.    drive like that in Silicon Valley?   every and I mean EVERY other car on the road will make a point of getting in front of you to fill in the empty space.

    I prefer “take a motorcycle, split lanes, flow like water”

    1. If motorcycles were only lane splitting on the freeway in jammed traffic — no more than 10mph faster than traffic and not going over 39 total — that’d be great, but that’s never the case. It’s used as an excuse to weave through traffic that’s already doing 75-80. To take the inside curve on an on ramp. On surface streets to beat traffic lights.

      It’s a shame because there’s conditions daily where it makes sense.

  17. Of course it’s just progression towards the solution which is “everyone stops driving” – everything else is just an argument ;)

        1. I thought that Yosemite Sam mudflaps were a coded way of offering a mustache ride.

    1. A person doing this is driving at exactly the same average speed as someone who is racing ahead then sitting still.  This is completely obvious.  You get there at exactly the same time, you just do it at a continuous speed, saving gas and wear and tear on the car, and also at a significantly reduced risk of rear-ending someone.

      1. But what’s the point of getting in the car if you don’t treat it like a video game?

  18. I’m so glad that instead of this, we spent time in driver’s ed looking at pictures of wrecks as though that teaches us how to avoid them.

  19. I do this as well. First, it lets your mind relax. That makes driving in traffic a lot easier right away. I let anybody pull in front of me that wants to, that eases other lanes. I keep moving and so do those behind me. If we all did this there would be far fewer true jams, and we’d get where we were going faster in the end.

  20. All this is doomed to failure. There is huge latent demand for road space. Decisions not to drive, or not to drive at peak hours because of traffic tend to be reversed as things are done to reduce congestion. It’s actually worse than that, as reducing congestion enables people to commute further and add even more to traffic. These is an equilibrium of tolerance for being fucked about that is hard to shift.

    1. Actually the road-space argument is wrong.  The graph of flow rate versus density has a peak.

      In congested traffic, if people try to tailgate and “pack more cars on the highway,” their attempts will backfire, and all the backups grow longer as flow goes down.  Instead if they Obey Sam and “Back Off@kvanh:disqus “, the flow rate goes up and the jams start shrinking.  It’s counterintuitive.Only when speeds are well above 35MPH, only then it does make sense to pack in more cars.  The highway then is operating on the other side of the peak, so tailgating does increase the average flow.See:

  21. Highway and city driving strategies are completely different.

    City driving seems to be about not getting caught at lights, and being in the right lane at the right time.
    And that is mainly anticipation and knowing what to look for, as well as knowing every little timing and quirk of the road you’re on.

    On a road with traffic lights that I drive nearly every day, when the light ahead turns green, I know exactly where and at what speed I need to be going to get through the intersection before it turns red.

    So yes, this is completely predictable. If the light is timed by cars at the cross streets, then look at the cars on the cross streets and start counting.

    I know where and which lanes have a high probability of coming to a standstill because of someone needing to turn left or right.

    Or which lane is perpetually underused because of a particular layout and traffic pattern.

    Calculated aggressive-ish(?) driving can cut
    my commute time in half on non-highways.

    That said, it’s quite satisfying when seeing someone drive like an ass only to get stopped at the light while you casually catch up to them.

    This is happens because they are doing it wrong. It’s not random speeding and cutting people off at the first opening you
    see that will get you ahead.

  22. On multilane highways, everyone can simply improve flow by avoiding touching their brakes. People make their brake lights flash without actually slowing, simply because they are nervous. This starts a chain reaction of panic and over-reaction.

    The reason driving slow and steady doesn’t work in my experience, is driving the same route teaches you the lanes are not equal due to merging traffic, etc. For example, the right lane of the Westway into London is faster on approach and all along Marylebone. Other cars join from the left, and leave from the right. I have conducted hundreds of experiments on this.  The right lane is much, much faster. Stick to the car in front to prevent opportunistic lane switching, which will cause waves. Wave eating in the left lane is fine; wave eating in the right in this instance causes chaos as it introduces *more* lane switching and punishes the more experienced, alert and scientific drivers on the route for the benefit of tourists and auto-sheep who don’t know any better.

    1. Because only LA has traffic jams.

      It takes me an hour+ to travel 27.5 km to work in Sydney and that’s going against the traffic! The same trip without traffic can be done in about 20-25 minutes.

  23. Google cars for the win! I CANNOT WAIT for this technology to hit the streets. It’s going to be a game changer – totally disruptive tech. Please please please Google do not put in any kind of override system. Do not let people apply brakes because they be scared. Do not let any human have a say in how fast their car is going. Just let it be we hop in our cars in the morning and do our crossword puzzles while being autopiloted around. That is all. Traffic, goodbye. I will be the first in line for my new Google car. Also, can you make mine look super awesome?

      1. I want a future of human trebuchets and drop rides instead of buses and elevators.

        Just say no to multipass.

        1.  Well, I guess that could be one reason for breakfast NOT to be the most important meal of the day.

          Reminds me of the one time I almost lost it in a vertical centrifuge at the fair, but managed to step off the ride before barfing.

  24. Something self-driving cars will solve for us, because most of us are really too tied up in ourselves to realize we’re not losers for letting other cars get in front of us. 

    1. Or just have a city hire some pace cars for rush-hour, like they do in Belgium.    The “Blokrijden” technique turns the clogged traffic into high-speed cohorts of cars, no automation required.

  25. I’m a bus driver, and this is one of the things that heavy vehicles do routinely.
    Some factors:
    I generally have good visibility of the traffic ahead
    I drive 40+ hours a day over familiar routes
    I have a three digit IQ

    Every now and then, I’ll make a point of noticing a lane-changing tail-gater and see how long it takes for them to get more than a few hundred metres ahead of my bus. Sometimes it works the other way and I’m waiting to see if they catch up to me! Until and unless they turn off, I rarely lose sight of them completely.

    The biggest lesson I learned as a bus driver is that we usually run on time, within only a couple of minutes. If we’re late, it’s because of a crash or roadworks or something similar that affects _all_ traffic, including those who think their adrenalin has some impact on everyone else’s vehicles.

    The cowboy bus drivers who push speed limits and change lanes and try all the tricks… mostly run on time, within a couple of minutes.

      1.  Actually, he’s driving the bus at near-light speeds, so it’s 40 hours a day *relatively*…

  26. AKA logic.

    Problem is that 50m behind you there’s always some douchebag recreating the traffic waves anyway.

  27.  Unless it’s a situation like the one in my video:   there’s a handle that says “fire sprinklers, pull to activate,” but everybody is too busy stomping faces and rushing the exit to notice.

    Just one driver.

  28. I do this. Its on a one lane road right outside my house thats super trafficy every morning, with a stop sign at the end. It works every time.

    That said I’m an aggressive driver, and will intentionally slam on the brakes to terrify tailgaters. Right before they hit me I roll forward to prevent it. Then they give you lots of room.

    You can also find a pal on the road doing something similar, match speeds with them, and even traffic out.

    Tell other people to do this every time you hear someone complain about traffic.

    1. Intentionally slamming on the brakes? That’s not “aggressive” driving, that’s being an idiot.

  29. Why doesn’t everyone just commute by helicopter like I do? BTW this would never fly in Jersey….NJ drivers barely can drive properly now, asking them to try a new technique would result in utter chaos.

  30. All I could think of when I read the headline was, “Slowly….driving slowly….can’t these f*ing boingboing bloggers use proper grammar?”

  31. If you visit Vancouver and happen to cross southbound over the Lions Gate bridge back into Stanley Park, it’s 4 lanes of traffic often merging down to 1.  You’ll notice that the drivers are scrupulously fair in alternating one after another to perform the merge.  After driving in some more aggressive environs, it renews my faith in humanity every time.

  32. Traffic is a nonlinear system and so there are places where slowing down helps and others where it hurts.   One thing for sure is that if you apply simple linear rules like always tailgate or always drive slow then you aren’t behaving in a way that maximizes throughput.  Just to take two examples:
    1. If you are braking more than the rest of the people around you then you are almost certainly part of the problem.
    2. If you aren’t speeding up when you pass an accident then you are almost certainly part of the problem.

  33. The UK’s M25 motorway reduces speed limits when congestion starts to build up to prevent what they call flow breakdown; if the system detects very slow moving or stationary traffic the speed limit drops to 40mph in the immediate area.

  34. This is what some junctions look like a lot of the time in my city. Just about everyone is always looking for that 2 second advantage, and many people will ignore traffic lights (including bus drivers, who will turn right in any case but will sometimes cross a full junction on red). You hardly ever get smooth traffic, but one of my old bosses was able to drive fairly smoothly in conditions not much better than this. He might not have influenced the rest of the traffic on the road, but at least we all felt much safer. He basically just stayed calm and avoided sharp acceleration, braking or lane changes. Another guy who would sometimes drive us was the opposite: always weaving in and out of traffic and acting incredibly aggressively towards other drivers. I travelled with them both quite often, but I don’t think there was ever much of a difference in time between the two.

  35. I am way too in to this.  I need to get a job with a shorter/no commute.  I can’t tell you how much time I spend thinking about ways to single handed improve traffic.  

  36. It depends on how you define a traffic jam. Do you have to stay completely still or is driving at an extremely low speed also considered a traffic jam?

    I understand that you can avoid standing still by leaving large gaps, but what you don’t consider is that you enlarge the length of the traffic jam. Better to drive for five minutes and stand still for another five minutes, than drive slowly for ten minutes for the same distance. At least people who want to take the next exit have a chance to do so.

    1.  The length of the jam is actually shortened, because tributaries join the flow more efficiently.  The effect isn’t sudden, but it does happen as the upstream-most fringes of the gradually drain into the core (filling in the gaps that had been caused by the stop-and-go).

  37. I hit some of the worst traffic a few years ago on I-76 going into Philadelphia and just put my car in drive but my foot off the accelerator. I went the speed of the stop-and-go traffic as well, and there was much less stress doing so.

  38. I’m curious to see how this would work in Finland. I lived in the USA until I was 20 and learned to drive there, but highways are a relatively new phenomenon for most Finnish drivers (as of 2011, there are only 779 km of highways in Finland, and Finland’s first “real” highway opened to traffic in 1962). As a consequence, a lot of Finnish drivers do not know how to merge. Instead of trying to match the speed of the traffic on the road they are entering, they simply drive to the end of the merge lane and stop until there’s a large enough gap. Needless to say, this causes major backups during rush hour, and the stop-and-go waves are a familiar phenomenon. I’ll have to give this a try the next time I drive (it’s so much easier to just take the train!).

  39. If you observe railway engineers and subway motormen this is just the way they operate their trains. They keep their trains at just the right speed to arrive at the next signal just when it changes. Not braking is a huge savings in fuel for a heavy train. I often wonder if these folks drive their own cars that way.

  40. I’ve seen large trucks doing this … and no one wants to argue with them.

    One of the wonderful unplanned consequences of photo radar on the freeways was that it kept most of the speedsters from starting waves as they zigged and zagged through traffic, making other drivers brake to avoid them and starting a wave.  Traffic flowed far more smoothly.    

  41. You may have solved traffic buy I’m sure you enraged many people… You’re lucky you didn’t get shot.

    1. Not many, (if any).  The gap isn’t necessarily visible more than one or two cars back.

      Quite the contrary is more likely, since the only change people in the traffic further back will have noticed is that the stop-and-go has ceased.   If anything, they’re more likely to be happier now that traffic seems to have started moving steadily.

  42. It pleases me how many people here say they already try to drive like this.

    I’d been trying to drive like this just to save wear and tear on my car; and I’ve noticed that many places when I do it, it’s contagious. The cars *beside* me start to do the same thing. I’ve driven in the UK and US, driving the length of the US a couple times a year, and this works *everywhere*, from Austin to New York. It’s worked in London, Athens, Singapore, and Bangkok (if you leave enough space, the tuktuks will flow around you like water. If you don’t, they still will, but your car is more likely to be damaged).

    Lots of people are saying “oh, my city is too macho for this to work” but that is actually BS: you are either making excuses not to change your driving, or you are misunderstanding what is being suggested. Your city is not special, and does not have its own rules of physics, for all that it’s an amusing fantasy. You do not have to drive at a perfectly constant speed; you just need to drive *somewhat more smoothly* than the surrounding traffic, which requires a *slightly larger than average buffer ahead of you*.  If everyone else is nose to tail, then even if you drive with just one car length ahead of you, then you are helping, because when traffic stops, you have to brake less sharply.

    Lots of people are also saying “this doesn’t apply where there are lots of traffic lights” – yes, it does. Don’t brake sharply at the lights. Coast a little. Brake sooner but more slowly. And what you’ll often find is that *you are still moving* when the light turns green, so rather than stop, you just move from brake to gas and breeze past the other lanes. There’s less wear and tear on your brakes, lower gas usage. The cars behind you will often copy your behavior, and you’ll end up getting through those lights faster.

    Sure, it’s a nice and tiny city, but I *enjoy* playing this game through Austin in rush hour.

    Drivers throughout the world recognize and appreciate good considerate driving, and show their appreciation by copying it. Seeing someone else drive calmly, *calms them*.

  43. Steady speed removes traffic jams, news at 11. Obviously. They are the opposite on the road, stuttering and inattentiveness cause backups and “waves” of braking – slowing and speeding without reaching their maximum allowable speed (legal and illegal). It wouldn’t be SINGLEHANDEDLY either, this would have to be written on a post-it note at the top of everyone’s visor! They’d also have to be able to see what you’re seeing to know when to apply this magic formula and when to start speeding up. This is the definition of a selfish driver, playing his inattentiveness to be a merit rather than part of the problem. This is where hub networks and car to car communication and smart cars come into play, but we are far from that at this point. We are talking about people, a broad range of people of varying levels of driving skill and behaviors. People who are sometimes unpredictable and who sometimes may be inebriated or using a phone. People who may be in a rush and are changing lanes aggressively, legally, to get somewhere.

    It is as close to impossible as you can get, thinking that you can get all people in the world to drive this way. There is no other way where it would be a solution, otherwise it would just be another kind of slowdown on the roads – just a slightly slower and smoother one. Even if you could get everyone on board, who starts driving slowly in the first place, how do you deal with sudden accidents? These are half ton vehicles going 70 MPH+ in California, mostly what people are thinking about is not dying or crashing – not trying to drive smoothly so the people behind them don’t have to stop and go. Yes, we all try to brake responsibly so that we don’t get rear ended but sometimes you don’t get that benefit. 

    Yes, this is A solution to traffic. Reduce traffic (stop and go slowdowns) by even spacing vehicles using an average speed. Of course, I think that’s exactly what solves traffic – by definition. It won’t work because not everyone can see what you can see and not every driver is headed the same way (could be getting off sooner than you) and not every driver is thinking about this kind of solution. Not every road is a straightaway, most are curved and have inclines or bad conditions such as fog or potholes. Even if you got the majority of drivers on the road doing this, I am certain that it would fail if that remaining percentage were speeding up to fill empty spaces in front of you. Unless that person from the article had a helicopter or satellite following him during his “experiment”, there is no way to know what caused the traffic behind him to mellow out. No way. I see steady traffic behind me all the time. Means nothing. He is capturing an instant and using it to define an entire trip. Incorrect. 

    What is the solution to traffic? Who knows, there are hundreds of published works on it yet there is none. Every region of the world has it own flavor of traffic: Beijing traffic is a million times different than backroads Tennessee which is far from D.C. where the drivers would feel foreign in Southern California. You can not possibly guess how drivers will react to situations or how they will behave when given a couple miles of traffic. Some will speed up and try to find a path through. Some will just go with the stop-n-go. Some will slow down and just do what the traffic tells them. Some people I know get off the freeway and do something else because they hate it so much. I think the less people on the roads, the better. This may be a wonderful solution to computer-aided vehicles that have information about upcoming road conditions and can communicate with each other. It’s not helpful for todays roads. We need people to pay better attention to the actions of the drivers around them, concentrate on the road in front of them, stop playing with their phones and drive according to the rules of the roads. Faster vehicles to the left and slower vehicles to the right. That is the best solution. Keeping vehicles with similar speeds together so that there is not constant braking or speeding up. Those are the best things we can do now. Using software maps and traffic information like bing or waze to keep off of already volatile roads and driving actively so that we are not causing more problems. Staying in a lane that matches our driving style. If you want to drive under the speed limit or are getting off soon, stay to the right. If you want to speed up, head forward on the left side. This works no matter if it’s a seven lane highway or a two lane back road.

    1. I wholeheartedly agree with “slower traffic to the right”, but you’ll realize this is irrelevant when you read the original post more closely.  (There was no mention of this needing to be in the left lane,  In fact, they even offered a mini animation showing the behavior taking place in the RIGHT lane).

       It actually does work, and a single person CAN accomplish this significantly, since reducing the number of gaps upstream results in all of those cars being packed more efficiently, with benefits to tributaries and intersections.  It works best in tunnels, I’ve found. Not only because lane changing is prohibited, but because stopping waves are very common (possibly for many different reasons – tunnel phobia, skewed distance perception within a closed space, whatever)

      The benefit of persistently smooth flow is that it presents the opportunity for all waveless traffic behind you to flow more efficiently into and through the city grid, as well, because it will have a higher density.

      1. I agree, this would help in a tunnel. One, maybe a couple, people driving at the average speed could ease stop and go traffic in a tunnel. As long as all the problem causing traffic is people slowing down. A closed system that has no people getting off or on throughout the passage. Just like the animation. The problem is that 99% of roads (hyperbole but close) are NOT tunnels or 2 lane straightaways like the animation. The real world is a bit different. Smooth vehicle flow, like I stated, is the opposite of stop and go traffic. The problem is that there are far too many other factors going into the stop and go slow downs. Accidents, inattentive drivers, novice drivers, people entering/exiting, aggressive drivers, road rage incidents, all change that dynamic so much.

        You stated one of the biggest reasons why this works in tunnels or smaller roads: because they aren’t allowed to change lanes or exit. Real roads are much different, every driver is going to a different location and coming from a unique place and time – all with different levels of urgency in getting there. Within reason, a tunnel balances all that. 

        Just because it’s in an animation, doesn’t mean that it’s correct. I think everyone agrees that slower traffic should move to the right, with faster traffic moving on the left. This allows for large amounts of vehicles to move past areas of other vehicles moving much slower, it also easily allows for vehicles to enter and exit. If that is the case, then if you are going to drive the average speed “smoothly”, you should probably be in the middle or right lanes. Until we can get cars that can communicate with each other and have information about upcoming road conditions as well as shared telemetric data, that’s the best we can do. Go to and type in traffic flow research. You’ll understand after reading a few. These are people who have taken the time and work, years of research – not an “electrical engineer” who posts some animations on a website. 

  44. A long time ago, I was being trained by a retired State Policeman in a class sponsored by my employer.  During a discussion of speed limits someone asked him what the safest speed was. He answered, “If you’re passing everyone, you’re driving too fast. If everyone is passing you, you’re driving too slow. One is as dangerous as the other.”

  45. Bravo –  I’ve done this in both the Lincoln and Holland tunnels in NYC and it works quite well.  In no small part due to the fact that lane changing is prohibited.  No one behind the wave-eating car can progress faster than the continuing waves ahead, so there’s no loss in absolute progress.

    The other benefit that no one has mentioned (so far as I’ve gotten): Start-stop waves cause pockets of low density (i.e. less efficient packing) in the city grid approaching the tunnel.  By reducing the number of waves moving backward through traffic, the throughput within the grid is raised, because more cars will make each light.

    1. As long as you are going the speed limit, more power to you. Wonderful idea in a tunnel, especially if the traffic in front of you is constantly speeding up and slowing down. 

      Not saying you are but it would be extremely selfish and egotistical to think that you are doing the right thing for all the people behind you in a tunnel when there are no vehicles in front of you or you are excessively slower than the speed limit. Right? How does a person decide what is “smooth” speed they need to drive at? Are they psychic? Can they see ahead in the tunnel? 

  46. the most retarded idea ever.
    the reason there is stop and go traffic is a-holes that refuse to keep up with the traffic in front of them.
    do you think the guy at the very front is going 35mph?
    he is going 70.
    but someplace behind him is a-hole going 60.
    and behind him, a bigger a-hole going 50.
    and behind him, another a-hole going 40.
    add enough a-holes, and you left with stop and go traffic.

    1. Nope, instead waves arise because of tailgating.   If *you* follow too closely, then your delayed reaction is making the waves slightly larger as they go past you.  A region of tailgating drivers is a wave-creator.   If everyone stops tailgating, then the waves fade away as they travel along.

      In traffic simulations, waves will still build up exactly as they do on a real road, even though every simulated driver is exactly the same.   No individual causes waves in traffic, any more than one asshole sand grain is to blame for sand dunes appearing.

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