[DanBC]

As one example of a crossing which does have warnings:

The A417 between Cirencester and Cheltenham is a dual carriageway that has pedestrian footpaths across it.

Imagine driving at 70mph toward this:

350 yard warning: https://www.google.co.uk/maps/@51.8078399,-2.0618748,3a,75y,...

actual crossing: https://www.google.co.uk/maps/@51.8051623,-2.0595278,3a,75y,...

350 yards at 70 MPH is, I think, 10 seconds.

[kwhitefoot]

That's about twice the stopping distance for a wet road so plenty of time to stop except that you can't tell until a lot later that someone might be about to cross because you can't see the pedestrian approach. I come from Swindon and drive that road quite often when I go back to visit family and I have never seen a pedestrian cross it. I certainly wouldn't like to do it except on a bright clear and dry day but I dare say that the locals might have a better idea of the risks.