[andrewflnr]

The way I do it, I eventually catch up to the car in front of me. Not having the data to pick the perfect, average speed, I err faster so that the traffic behind me isn't, on average, going significantly slower than traffic in front of me. Note that waves behind you are the only waves affected. All you're doing is thinning out the medium so they don't propagate efficiently. The end goal is keeping actual speed close to average speed; spacing is a means to an end.