exit to exit timing on toll roads

We don't have toll roads, as has been explained further down the thread, but what is now being introduced here are gantries with cameras that read your number plates at the beginning and end of a section and calculate your speed. People have been coming up with patent ideas to make number plates unreadable!

I didn't think it could work that well until I was going through some roadworks on a motorway and a large flashing light display came up with: Slow down - driver, followed by my numberplate, followed by my accurate speed.