pace cars for motorways

This is inspired by waugsqeke's quantized speeds for cars, and a couple of other car:speed ideas, but i think it has the legs to stand alone as an independent idea.

For long distance highways / motorways there is a higher overall traffic throughput when speeds are standardised along the whole route. If there is, say, an accident heavy traffic that reduces the average speed of drivers at point x, those drivers who are coming from point y will race up behind the slower traffic and create a tailback.

What I would propose is a system of pace cars, that hold the traffic at a series of calculated speeds to keep overall traffic throughput at an optimum.

There would be a number of ways of implementing this. I envisage something the like of tax breaks for commercial drivers / salesmen etc. to have speed regulating equipment hardwired into their cars.

Coupled up with some sort of RDS feedback to a central computer this will provide a map of overall traffic flow along the entire route, facillitating the calculations necessary to optimise traffic throughput.