Traffic
Being a resident of Los Angeles, I occasionally find myself trapped in traffic. Having ample time, my mind will wander, and I'll imagine that one of those new-fangled hydrogen cars has suffered some unfortunate act of chemistry and detonated in the middle of the HOV lane, spewing molten aluminum everywhere and generally wreaking havoc amongst those cars unfortunate enough to be nearby. I'll postulate that the LA fire and rescue has sent a battalion of helicopters to shuttle survivors to nearby hospitals, and they are using my lane as a temporary landing pad, which is the only plausible reason for this terrible traffic. Without fail, the car ahead of me will suddenly accelerate, and the highway will clear without explanation. No helicopters. No police. No fiery crater in the middle of the road.
I find this annoying, but it is easily explained.
Simulation
The simulator attached below gives you an overhead view of a road. If the road looks like a huge grey box, you probably need to update your java install. Let the applet run for a second to see that the road can readily handle the traffic flow when everyone maintains a steady pace. Clicking anywhere inside the box will "distract" one of the lead drivers such that they slow down — similar to slamming on the brakes. Do this for a few seconds until two or three cars are stopped. What you should notice is that the halted cars clump together. Also, you should note that this clumping travels backwards away from the origin of disturbance.What you are seeing is a compression wave. If normal traffic flow is considered to be a medium like air, the disturbance in steady flow creates a compression of the medium that radiates away from the source much like your voice propagates as compressions in the surrounding air.
The fact that the wave propagates explains why the source of the traffic jam is often not near where the traffic will clear up. By increasing the density of the incoming traffic, you can also see how intolerant of minor disturbances a heavy flow can be. Increase the traffic rate and note that halting as little as two cars can cause a jam that fills the entire screen! This implies that the hour you spent in traffic this morning may be little more than the remnants of a near collision when someone was messing with their stereo.
Solution
As you can see, the reason for the problem lies in our ability to brake much more quickly than we accelerate. Of course, this is not the problem for certain vehicles, and there lies the solution. A shinier car with a little more oomph under the hood can clear the jam much more quickly. You can see this by increasing the car power in the simulation. Notice that the jams will now self clear themselves.Unfortunately, these cars tend to be rather pricey — a problem that can be easily sidestepped by leveraging the massive buying power of our government. Specifically, we should convince the government to buy us all faster cars. This only works if we all get one, so try to bridge that massive political chasm between you and your neighbor and rally under my new PAC, "People Who Want the Government to Buy Us Sports Cars." Like all other random internet political movements, this one will consist primarily of a form letter that you should send to your congressperson. Yeah, the one whose name you know. It will simply state the purpose of your movement and end with an impassioned plea for the environment, which should be fairly simple in this case — less traffic means less pollution, which is good for all the fluffy animals.
I have attached a sample letter for your use.
Dear Senator:
Traffic here is terrible. Please enact legislation
that will provide me and everyone else in your constituency
with a turbocharged Lamborghini Dominator with a twin phase
flux ion intermodulator, r-type sticker package, a 5.7 Liter
Wankel rotary engine, and a juicy 0-60 time of 3.6 seconds.
Please, think of the whales.
Yours Truly,
Screamy Guy