Traffic Hacks: How One Driver Can Vastly Improve Traffic

I changed my driving patterns after first reading this remarkable essay some years ago. Now I follow what I affectionately call the "zen of driving", to wit: leave a huge gap in front of me, drive at a constant speed where possible [1], avoid using the brakes except in case of emergency, and so on.<p>On long driving trips through mixed traffic, I have made several observations, some obvious and some surprising:<p>* Driving in congestion is no longer stressful. It just isn't. (Hence the "zen".)<p>* Dramatically improved fuel economy.<p>* It's possible to drive through even wildly erratic traffic (swinging from 100 km/h to 20 km/h) without ever touching the brakes. It becomes a kind of game. Manual transmission helps.<p>* Some other drivers seem to figure out what I'm doing, and they fall into place behind me at a reasonable distance. I've had people follow me for hundreds of kilometres this way.<p>* Even though you'd assume leaving a huge gap in front is an invitation for other motorists to cut ahead, they rarely do - especially in congestion. If they do, I just let them race up to the front of the gap and then fall back by a single car length to restore the same gap.<p>I absolutely swear by this driving method. It's easier on the car, easier on the heart, and even serves to create a bubble of calm around you in an otherwise turbulent flow of traffic.<p>------<p>[1] Edit to qualify "drive at a constant speed". As I noted later, my speed ranges dramatically based on the congestion level - what remains more or less constant is the safe opening in front of me. Sorry for any confusion with my original choice of words.

This man is a saint. For years I've wished more people understood these principles. Instead, I get drivers who are angry at me for leaving a big space in front of my car. If only I pulled up right behind the car in front of me, they'd be 60 feet closer to their destination!!<p>I wish more people would check this site out. Traffic is a <i>real problem</i> that wastes billions of taxpayer dollars and hours on the road every year.<p>Another idea to make the roads better: lane-specific <i>minimum</i> speeds. Think about it. It would actually solve a ton of common traffic problems.

Some Japanese scientists did a study to show how traffic jams can appear of of nowhere. They told 22 drivers to drive in a circular path at 30 km/h. A traffic jam appeared, and moved backward. The video is here: <a href="http://www.youtube.com/watch?v=Suugn-p5C1M" rel="nofollow">http://www.youtube.com/watch?v=Suugn-p5C1M</a>

Ever since I can remember, I've always thought this was obvious, a product of random slowdown being amplified by reaction time delay. Motorway pileups are well known to be exacerbated by close driving, because each subsequent driver has to brake harder and harder to stop. Jams are just a less dramatic form of the same thing.

"WHY must a bottleneck develop at a merge zone? Well, obviously because there's too many cars on one road. And because everyone must take turns slowly merging together. WRONG! Wrong wrong wrong. Even during extremely low-traffic conditions, everyone still takes turns, yet everyone merges as a high speed flow,like a zipper. A bottleneck never appears."<p>New York city drivers are really excellent at the zipper merge thing. While living there, I got really used to not having to slow down much at merge points. Everyone just drove at a decent speed using all available lanes then smoothly merged at the point where the lane was closed.<p>Moving back to Pennsylvania, people start queuing up in one lane a mile before the merge point, and traffic grinds to a stand still. This is insane. Usually, though, if you do the sane thing and use the other lane up to the merge point, you can get in without trouble.<p>Maybe I was one of the early mergers before I lived in New York, and have just blocked it out of my memory. Now, though, seeing it happen really grates on my nerves. One of many reasons I'm glad I hardly ever drive anymore. :)

I've been driving like this ever since I heard a show on Wisconsin Public Radio where they interviewed a traffic researcher. One thing that is <i>not</i> true, however, is that "cheaters" are always wrong.<p>For instance, there is significant research that suggests in a 2 lane situation where both lanes must merge into one single lane (road work ahead, for example), it makes more sense for both lanes to proceed uniformly toward the point where they must merge. Most people would assume this would cause a deadlock at the point where the merge occurs, but it doesn't. When both lanes are allowed to proceed without switching lanes towards the point where they both must merge, they will achieve far better results than if they were to organize into a single lane prior to that point.<p>This makes people /really/ angry. Once, when there was approximately 2 miles notice for road work, I stuck with the right lane and did not merge into the left lane like everyone else. I actually had a large pickup truck attempt to cut me off from proceeding in an EMPTY lane.<p>Of course, this only holds when there is an inevitable traffic jam. When it comes to /avoiding/ traffic jams, you are better off maintaining distance to allow other drivers to merge.

It saves a lot of gas too. I've always tried to get through stop and go traffic smoothly without using the brake, but I always did it for my own gas consumption. I never had this macro look at it.

Doesn't this imply that cities could alleviate traffic pathologies by hiring people to drive carefully down the highway?

i think its interesting that i used to drive like this site describes for the exact reasons it talks about. and now i don't/can't. the difference? i moved to atlanta.<p>rush hour drivers here operate under a greedy algorithm. they see an opening that will allow them to speed up or gain extra distance immediately, and they'll take it, for no other reason than to be going faster right now, to be farther down the road right now.<p>and that includes eating up my buffer zone, forcing me to break/stop, killing my flow optimization.

I'm a fast driver, and one thing I will never understand are those who will do anything and everything to box in a fast driver, or to prevent them from cutting into a lane and taking off. I see fast drivers as excited molecules, looking to escape. What often happens when a fast driver is being blocked is they'll switch lanes back and forth, looking for their escape, creating this wave of hesitation, causing this big low speed anchor to form.<p>Someone driving fast won't suddenly stop the speeding after being blocked. Just let them go!

I read this a while ago and I try to do it whenever I find myself in traffic. If nothing else, it is immensely less frustrating to drive a constant 15mph than to drive 30mph half the time and be at a complete stop half the time.

While I have not conducted any format experiments in the efficacy of the advocated driving method, I can report that it's far more relaxing than tailgating. Give it a try!

When I accidentally end up on Rt 128 at rush hour, I do this.<p>(I note that I was on a mailing list with a bunch of relatively smart people once, and I mentioned what I did - and even among the smart folks there was a lot of outrage because I was driving "wrong" or "stupidly".<p>That reaction contributed to me leaving the list shortly thereafter. )

Interesting, my instinct has always been to try to "punish" the cheaters by preventing them from merging in, thinking that this would discourage this behavior. But I can't really stop this, and the article provides a good explanation for why you might as well just let people merge in front of you.

For anyone else fascinated by traffic patterns and driver behavior, I recommend reading Traffic: Why We Drive The Way we Do and What It Says about Us<p>The author goes into fascinating detail about driver psychology and discusses similar ideas like those mentioned in the essay.<p>Link to book: <a href="http://www.amazon.com/Traffic-Drive-What-Says-About/dp/0307277194/ref=sr_1_1?ie=UTF8&#38;s=books&#38;qid=1251250678&#38;sr=8-1" rel="nofollow">http://www.amazon.com/Traffic-Drive-What-Says-About/dp/03072...</a>

I've actually done this on my way to/from work, and it makes a legitimate improvement in my commute.

<i>How One Driver Can Vastly Improve Traffic</i><p>Yes, but that one driver is <i>never</i> the guy in front of you.

I respect this guy's patience, but the primary reason that one car can make such a big difference in this case is because 520 (one of the most important commuter roads in the Seattle area) is just two lanes in each direction. One car on a three lane road will just be passed.<p>The counter-point to this, in my opinion, is that at some point psychology comes in to play and you have people starting to get aggressive and angry because of a few people forming a "rolling-road-block". It's not rational but it definitely happens.<p>I would support 3PM-7PM dynamic speed limits on 520W toward the bridge. If the speed was brought from 60 (just past 405) to 30 as you approach the bridge it could probably keep things moving smoothly through the traffic burst.

I read this site a few years back and I've done a bit experimenting. I'm convinced that leaving space in front and avoiding sudden changes on speed are really helpful. Some times I have even seen traffic jams disapear if I leave a lot of space in front.

This essay should appear as a Public Service Broadcast through all media outlets.

My biggest complaint about this is that it's going to give many people who don't <i>actually</i> help traffic, and just drive slowly, feel self-righteous about their driving habits. Yes, in some circumstances this driving style can help traffic; no, it doesn't mean that driving 15MPH slower than ambient traffic is justified "for the greater good", especially if you're the type who jealously guards the thirty car lengths in front of you, accelerating to keep people from changing lanes in front of you.

Nice, patient guy but there's a better way yet if you can afford to gamble with your time a bit (don't try this if you can't afford to lose a little time).<p>When confronted with a single backed up lane, use the uncontended lanes to zip to the front of the wave and merge in _at speed_. Maintaining speed is important. If you don't find an opening, you'll have to abort and find another route to your destination.<p>The up-side is that this almost always pays off and you waste little time slowed by traffic or slowing others. The reason is because many people who queue up resign to the monotony and pull out their phone or their air drums, etc. They pay enough attention to brake consistently but not enough to accelerate as soon as is possible.<p>The vast majority of the time, you can slip in front of one of these 'sleepers' before they notice the opening or have fully accelerated. Because of inertia, they will go through an acceleration period where you pull away from them leaving them a very sufficient gap.<p>Another way to look at this is using the available real-estate to ascertain a proper zipper-merge. If done right, you wait less and no one gets stuck behind you. This is especially useful if you commute five days a week--the payoffs over time are well worth the occasional crap out.

"Constant velocity" applies to lane changes, as well. I hate when people are going 70mph and slow down to the 55mph of the car in front of them, THEN change lanes. No, change lanes as you're coming up on them so that you maintain a constant velocity.<p>Related to this is the need to "stay right". Especially in CA, some of my fastest travel happens in the far right lanes because people think of lanes as a "speed" rather than a "function", and so the right lanes are empty while the left lanes are crowded and slow.<p>The number one lane is not the "fast" lane, it's a "passing" lane. Guess what? The number two lane is a passing lane, too. If you're not passing anyone, you should be on the far right side of the road.

This is a representation of classic game theory. If all participants cooperate to drive as described, the traffic clears. If nobody else helps to open up space, however, you will personally arrive at your destination slower by driving passively, even though many others behind you will benefit. And since this type of driving requires some degree of altruism, you can pretty much rule it out as a realistic outcome without introducing another constraint (eg. as mentioned in the article, state troopers merging into traffic and forming a rolling barricade).

I completely agree with the moving wave! I have pondered this very same pattern myself. I'm excited to see it documented and shared on the web.<p>Taking this "zen" driving a step further and imagining an ideal world of cars that never break down on the highway and where the process of merging onto and exiting from a highway could be scientifically mastered such that the speed of the nearby cars is at most nominally affected, it is not inconceivable that cars could travel at speeds far beyond what is considered safe today.

My friend and I have designed, in our 6th semesters, a 8085 microprocessor based, congestion-aware traffic control for crossroads.<p>The system uses switches on the roads ( replaced using RFID or other sensors placed on the ground or at the sides of the roads ), that detect the load on each path and route traffic accordingly.<p>Not much, but it worked like a charm !!

Makes me think of Drum-Buffer- Rope from Theory of Constraints. Maybe we need a pull system for roads. There are a few onramps on criminally undersized (due to nimby nutsos) highways in my area where a traffic light limits flow onto the road at busy times- smart. Then the same people put in stoplights at the ends of the offramps, backing traffic up onto the highway.

BTW, sorry if this sounds off-topic, do you know any good books/articles on Traffic? I'm very much fascinated by this too. Thanks.

While I find letting the 'cheaters' in grates too hard on my soul I alway try to practice driving at the average speed and avoiding using the brake. If for no other reason than to avoid wear on the car (in the UK most cars are still manual and so each start is a tiny bit more wear on the clutch as well as the brakes).

Kinda related and interesting/amusing - "This Guy Can Get 59 MPG in a Plain Old Accord. Beat That, Punk.":<p><a href="http://www.motherjones.com/politics/2007/01/guy-can-get-59-mpg-plain-old-accord-beat-punk" rel="nofollow">http://www.motherjones.com/politics/2007/01/guy-can-get-59-m...</a>

One has to wonder whether same principle can be applied to economics.<p>I.e. that continous and moderate spending instead of savings somehow keeps the wheels moving in the economy.

This works, but the trouble comes when some guy in a big truck starts heavily tailgating you and flipping you off.

If you want to help traffic, stop hitting your damn brakes so much. Brakes are for strong deceleration, and most deceleration in traffic can be handled by letting off the gas. Once you get good at this, follow as closely as possible in a traffic jam without applying your brakes.* There's nothing better a skilled driver can do to alleviate a traffic jam. The jam is physically shorter and people behind you are less likely to apply their own brakes as a result of these measures.<p>* This has the added benefit of making for a smoother ride, which also encourages those behind you to ease off the brakes.