While driving in traffic this morning I was once again considering this. I've come to greatly enjoy coasting my way through traffic (not using the gas or breaks when there is traffic), the great gas mileage it is giving me, and the patience I've obtained (it is easier to be patient when you're moving...no matter how slow).
But today I had a cynical idea. Could one use the same theory to create a traffic jam? Could one create a jam of rush hour proportions? I guess if you got your buddies together and formed a "wall" across the highway this would work, but could one car cause it? I'm guessing yes. We've seen the minor jams before when someone is moving incredibly slow. I'm guessing you could bottleneck traffic by moving 40-45 mph in one highway lane requiring everyone to pass you in the remaining lane(s). This alone, on a busy enough highway, could possibly create a jam.