I copied this from a the website: HERE. (It comes with a neat video too). I stumbled onto this myself a while ago and it really does work. Please copy and spread it around if you will. If we all get together and do it, it could really make a difference with road rage.
Don’t try this in the fast lane. For some reason it makes drivers crazy when you try to do this in the fast lane. He was doing it in the fast lane in the video but I think that was only because it was an exit lane.
AND A CURE FOR WAVES & JAMS
1998 William Beaty Electrical Engineer
My first ‘experiment’: accidentally erasing traffic waves!
Once upon a time, years ago, I was driving through a number of stop/go traffic waves on SR 520 at rush hour in Seattle. I decided to try something. On a day when I immediately started hitting the usual “waves” of stopped cars, I decided to drive smoothly. Rather than repeatedly rushing ahead with everyone else, only to come to a halt, I decided to try to move at the average speed of the traffic.
(with me if was because I wanted to save my old clutch)
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 the huge empty space ahead of me, but I knew I was driving no slower than anyone else. The space would open up, but then it would shrink to nothing again. Sometimes I hit it just right and never had to touch the brakes at all. Other times 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 rear view mirror. There was an interesting sight.
It was dusk, the headlights were on, and I was going down a long hill and across the bridges. I had a view of miles of highway behind me. In the neighboring lanes I could see maybe five of the traffic stop-waves. But in the lane behind ME, for miles, TOTALLY UNIFORM DISTRIBUTION. In the past I’d never realized it, but by driving at the average speed of traffic, my car had been “eating” the 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. My single tiny car had erased miles and miles of stop-and-go traffic. Just one single “lubricant atom” had a profound effect on the turbulent particle flow within miles of “tube.”
It’s always a good idea to drive without changing speed and without competing with other drivers for bits of headway. I’d always assumed that the reasons were philosophical rather than practical (i.e. try to be a calm, nice person.) But my above experience shows differently. A single solitary driver, if they stop “competing” and instead adopt some unusual driving habits, can actually wipe away some of the frustrating traffic patterns on a highway. That “nice” noncompetitive driver can erase traffic waves. I suspect that the opposite is also true: normal highway competition CREATES the traffic waves.
Suppose we push constantly ahead, change lanes to grab a bit of headway, and always eliminate our forward space in order to prevent other drivers from “cutting us off”. If tiny traffic waves appear, we will rush ahead and then brake hard, leaving larger waves behind us. Repeated action causes the waves to grow. Ironic that the angry people who push ahead as fast as possible might unwittingly participate in “amplifying” the very conditions that they hate so much. The solution seems obvious: drivers with a smooth “calm” style will tend to damp out the waves and produce a uniform flow… and the few drivers who intentionally drive at a single constant speed will wipe out the waves entirely.
I rarely commute on 520 where the really good traffic waves appear. I started to miss the opportunities to cancel them. However, I soon realized that the same process could be used to affect the smaller traffic jams too. “Traffic waves” are simply a series of small traffic jams with constant spacing. Each little jam is destroyed when a large empty space approaches it from behind. If no new cars are feeding into the jam from behind, yet cars are leaving from the front, then the jam is eroding away. If the jam is small enough, or if the empty space is large enough, then one single car can entirely annihilate the jam, as I had done with traffic waves.
But this means that just one single car, can change the behavior of everyone behind it. And soon those people behind that single car will replace everyone who’s currently in the jam. Your single car can bite a huge chunk out of the region of stopped traffic. If one car refuses to pack together with everyone else to form a “parking lot,” the jam can be made smaller. If one driver gradually builds up lots of empty space, perhaps that driver can “eat” the whole slowdown just as I’d “eaten” the many traffic waves using my own car.
(I’ve noticed that this traffic busting seems to effect the traffic ahead too)
On my evening commute on I-5 southbound from Everett there is always a right-lane traffic jam at one of the Lynnwood off-ramps. Close-packed cars must crawl along at 2mph for a very long time. Therefore I intentionally changed to the exit lane as I approached that distant jam, and I started letting a REALLY huge empty space open ahead of me. By the time I hit the jam, there was maybe 1000ft of empty road ahead. Sure enough, my big empty space stopped traffic from feeding it from behind, while the front of the jam kept dissolving as usual. By the time I arrived, the jam was significantly smaller than it had been. Amazing. This wasn’t any little traffic wave, yet one single driver was able to take a huge bite out of the back of it. Just moving jam around
Obviously my actions did more than just reduce the size of the jam. In order to create the empty space, I was temporarily driving about 10 mph below the speed of the heavy traffic. I did this for several minutes, and therefore I caused a slight slowdown behind me. After I arrived at the jam, the jam was smaller. When all was said and done, part of the dense traffic jam had been removed. However, it was changed into a mild slowdown, and it was spread backwards upstream over perhaps a mile of traffic. Traffic behavior was changed. Rather than driving at 50mph only to crawl along through a traffic jam for several minutes, everybody was now driving at 40mph for a few minutes before the jam, but then having a much smaller traffic jam to endure. The average traffic flow might have improved, but also it might have remained unchanged. But some of the nasty, frustrating part of the 2-mph jam was converted into a large “fuzzy” area of reduced speed. And after I made these changes, drivers as a whole would find it much easier switch lanes to avoid becoming trapped in the jam, since the solid-packed region was much smaller. If I had done it correctly, I could have erased the whole jam, transforming it into many minutes of slightly-slow driving for everyone behind me. (If I could have started 30mi upstream of the jam, maybe I would have only needed to drive 3mph slower than traffic… that is, if other drivers didn’t simply go around my slow car.)
Another thing that happened: by shrinking the region of solid-packed cars, I made it easier for other cars to merge into the exit lane, so I probably removed part of the backup in the through-lane as well. By moving the jam backwards, I unplugged the merge zone at that exit. The jam was mostly caused by drivers trying to merge across lanes to reach the exit. Drivers already in the exit lane weren’t letting anyone in, so the merging cars sat unmoving in one of the thru-lanes, waiting for a space to open, and also forcing everyone behind them to halt. So, by inserting a large empty space, I wasn’t only taking a bite out of the jam ahead of me. I was also easing the jam in other lanes. At best, moving the jam backwards would entirely remove the bottleneck and halt the growing queue of stopped cars. With the jam broken up, the clot of cars behind the merge zone becomes a wave which freely moves backwards. The traffic jam was like downtown city “grid-lock,” and I was breaking up the gridlock and promoting free flow by putting spaces between all the cars.
Here’s a general principle I take from the above. (I guess it’s obvious in hindsight!) ANTI-TRAFFIC DESTROYS TRAFFIC. Empty spaces (anti-traffic) can break up a traffic jam. While I was slightly slowing down to allow a space to gradually open up before me, I was creating an empty pulse of “anti-traffic” ahead of me. When my anti-traffic finally collided with the dense “traffic” of the jam, the two annihilated each other like a positron meeting an electron. It’s nonlinear soliton physics. The soliton waves destroy each other, leaving only a slight fuzzy smudge behind. The fuzzy smudge may behave very differently than the original bottleneck: it can travel backwards and move off into the distance.
While doing all of the jam-canceling above, I once caught myself behaving normally and creating a huge traffic wave. What a hypocrite! Bad habits die hard.
Traffic was heavy and I was in the left lane. I had to merge across several lanes in order to get to my exit. I merged right once, but the next lane was packed solid (but it was still moving, not jammed.) Nobody would let me in. I drove like this for a long while, then started driving fairly slowly in order to drift backwards along the solid lane. I found a slot and got in, but now I had to merge right once more. Many minutes had passed, and my exit was coming up. The right lane was packed solid, NOBODY WAS LETTING ME IN. I drove slower and slower, and in a panic I finally forced my way into a small gap, making the guy behind me jam on brakes. After awhile I realized that I had just created a huge traffic wave with my behavior. Just like any rubbernecker I had suddenly slowed way down for no good reason. But I had an excuse, I had to get to my exit! To make matters worse, I had nearly come to a complete stop, and brought two entire lanes of traffic to a near halt too. I probably left a long-term traffic wave at that spot on the highway. But it wasn’t my fault! Yeah, suuuure.
In stewing about this I realized that EVERYONE has this same problem at that particular spot: an inability to merge in the dense traffic. Others were probably doing the exact same thing that I did, and this would make the “wave” near that exit worse and worse. Our inability to change lanes would create a “dynamic bottleneck” which hovers near the exit. Obviously the simple cure is to give up; not merge, and miss the exit. I should never have forced the issue, I should have let my exit go past. So should all the other merging drivers. But there is a bigger issue here. People SHOULD be able to merge. Why was traffic packed so tightly? One obvious reason: to punish the idiots who will jump into any little space. I had always done the same myself. I never allow a space to appear ahead of me, or some other driver will immediately swerve into it during their quest to cheat by running down an empty lane to the front of the line. But this sort of “closed-gap” driving would also prevent any necessary merges at off ramps (and at on ramps too, of course.) By eliminating the space ahead of me, I become part of the impenetrable wall which creates the “dynamic bottleneck” and screws up the traffic at highway exits. The gear teeth cannot mesh, so the whole machine grinds to a halt. The “zipper” becomes jammed because the “teeth” of the zipper are resentful about new teeth moving into the space ahead of them.
The jammed merging lanes are much the same as gridlock in a city. Smart city drivers never block intersections, since blocked intersections will freeze all traffic permanently. But we highway drivers are ignorant. We close up the gaps when others need to merge. And our behavior creates needless “highway gridlock” during every single rush hour.
So, if I keep a few car-lengths of space open ahead of me, then not only can I use it to help vaporize waves and jams, but I also eliminate one of the major causes of the waves and “highway gridlock.” I eliminate the “solid wall” of traffic at merge areas, and I let people merge without slowing down and creating traffic waves behind them. Ideally a merge-area will act like high speed gear teeth. A “Zipper Merge.” But suppose that everyone starts defending themselves against opportunistic drivers by eliminating all gaps in traffic. In that case the valid merges cannot take place either. A fight develops, and a traffic jam is created. The jam appears at the merge zone, while a huge region of empty roadway is created downstream. Sometimes this jam is the fault of people like me who panic while missing their exit and who come to a complete stop. Sometimes the jam is the fault of the huge blinking yellow Construction Arrow which blocks one entire lane of traffic during road work. But the traffic jam is ALWAYS the fault of those who refuse to let anyone merge ahead of them. “Just merge behind me.” No, that doesn’t work, since the guy behind you doesn’t want any merges either. Everyone in the whole lane is saying “merge behind me!” It’s a solid packed wall of hostility. Poking any small hole in that wall can make a difference.
The BIG question
But does this increase the throughput of the highway? YES!!! It allows people to merge again! It actually changes the ‘capacity’ of the highway. It wipes out a ‘dynamic bottleneck.’ By removing the close-packed region, the two lanes of traffic at the exits and entrances are able to merge at high speed… so even though the close-packed region is now a big fuzzy slowdown, the flow of traffic does increase significantly.
On the other hand, the situation is not so simple if lots of extra traffic is entering from numerous on-ramps. The “rolling barrier” can’t affect these extra inputs, and if nearly all of the traffic is from on-ramps, then the “rolling barrier” idea would be worthless. In that case it can only control the main highway and not all the on-ramps.
But won’t other drivers simply go around me and fill my big empty space? Hmmmm. After trying this many times in many places, I find that they usually don’t. I wonder why?
A ONE-MAN MULTI-LANE ROLLING BARRIER
In driving with huge empty spaces during rush hour, I find that the space ahead of me doesn’t just instantly fill up. Other drivers don’t change lanes to fill them. Weird! What’s going on? First, if I’m driving with a big empty space, sometimes (rarely) the car directly behind me will pass me. Sometimes it happens twice. But this removes the lane jumpers from behind me, and forms a row behind me of non-aggressive drivers. Those drivers are like a plug, since any aggressive drivers many cars back can’t even SEE the big empty space ahead of me.
But what about the adjacent lane? Won’t they all fill my empty space? Nope. A few do change lanes, then they rush to the end of the empty space. This filters out the aggressive drivers from the adjacent lane, leaving sane ones next to my empty space. They don’t change lanes. They don’t care that there’s a huge empty space growing and shrinking right beside them. They form a big plug, and aggressive drivers behind them cannot get to my big empty space.
(I find that there’s an empty space that opens up next to me)
This “plug effect” seems only to happen when traffic is highly congested. When traffic is light, I can’t maintain any really extreme spaces, since aggressive drivers can easily swerve around to jump into the space. But when traffic is light, traffic jams are minimal, so there’s not as much need to create an anti-traffic bubble and perform some jam-busting.
Have you ever noticed when your highway lane ends, anyone merging earlier than you is a coward, and anyone merging later than you is a cheating lane-zoomer?
MAKING A REAL DIFFERENCE
During a year of practicing the “wave-smoothing” driving habits, I kept looking for places where I could make a big difference in traffic flow. Yes, I could always use an empty space to move a piece of the traffic jam to another location. With a big empty space, I could even spread the cars apart as I moved the slowdown, the same way I did it with the jammed sections in the “traffic wave.” But the genuine “bottlenecks” seemed all too rare. Then finally I noticed that there was one common situation where I could do some real good.
If you drive in heavy highway traffic, you’ve probably seen a traffic wave develop at a construction site where one lane is blocked for a long distance. You crawl and crawl at 3 mph until you get to the start of the bottleneck, then you take your turn merging as the two lanes sloooooooowly come together. Then you race off down the single lane at 60 mph! No downstream congestion! The merging lanes formed a terrible bottleneck, but they did not add together and overload the single lane downstream. The bottleneck was not the downstream lane itself. Instead, a stalled “traffic wave” develops at the merge-zone, and extends far back into the double lane. After the wave, in the long single lane, it’s clear sailing.
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 and high speed conditions, still everyone must take turns. Yet everyone merges as a high speed flow, like gear teeth or like a zipper. A bottleneck never appears.
Traffic jams develop at a merge zone whenever the cars momentarily get so close together that there are no gaps between them. Without gaps, nobody can merge, and so the traffic suddenly comes to a near halt. The “gear teeth” jams up, the “machine” halts, and a bottleneck is created. The pile of pebbles all block each other and can no longer pour through the funnel. Then traffic on the highway becomes something like a city street intersection, a “four way stop” where people pack together and take turns.
But whenever traffic comes to a near halt, people always pack themselves together.
Huh. This is screwy. At the place where the lanes merge together, close-packed cars cause the bottleneck, but… the bottleneck is the CAUSE of the close-packed cars. And also, the close-packed cars keep the bottleneck in existence. And the bottleneck causes the clot, it makes drivers all pack together and start tailgating.
Do traffic jams CAUSE THEMSELVES? After thinking about this even more, I realized that the answer must be yes. It goes like this:
Traffic is going slow.
Everyone packs together and closes up the gaps.
Fast merging becomes impossible.
The incoming cars will grow a huge long back-up.
Cars must slooooowly take turns merging.
This makes incoming traffic slow down.
Repeat this loop over and over.
This is absolutely fascinating because this self-caused situation has a counterpart:
Traffic flows along rapidly.
Nobody closes the gaps (they follow the 2-second rule?)
Merging is easy.
Streams of traffic flow together like a zipper.
This allows traffic to go fast.
Go back to the top of this loop and repeat.
At a merge zone, fast traffic causes traffic to remain fast, while slow traffic causes a jam to persist. Weird! The difference in flow rate between these two situations is enormous, yet EITHER ONE can arise on the exact same highway under the exact same amount of incoming flow. In the first one, the speed might be 2 mph, while in the second one it could be 40 mph. And here’s the important part: because the situations create themselves once they are established, sometimes they can switch from one to the other. A smooth flow can hit a glitch and turn into a traffic jam. Or somebody can switch them intentionally.
Suppose the traffic at a merge zone was flowing fast as in Loop Number 2 above. Suppose I wanted to wreck everything. I could get in the through-lane and slow way down. Fight with drivers in the other lane, trying to block them. Make all the cars pack together behind me. This would prevent any cars in the other lane from merging into my closely-packed lane. Cars in the merge-lane would then pile up too. Then I drive off laughing evilly, because I have just CREATED MASSIVE LONG-TERM TRAFFIC JAM! The exit might stay jammed for hours.
Or, I could do the opposite. Suppose everything is jammed up at the merge zone. Suppose I accumulate a huge space ahead of me and bring it in through the through-lane. When the huge space gets there, cars in the ending-lane can suddenly change lanes into my space, spread out, and start flowing fast. Next, I speed up and merge with them. The cars behind me do the same. The “zipper-like” flow has begun. The switch has flipped. I have just ERASED a long-term bottleneck. As they say in those old Ranier Beer ads, pretty cool, eh?