gg1
Established Member
The Aston Expressway in Brum still has them.Tidal flow signals on gantries above major roads - not sure if they still exist anywhere now. They consisted of a square box showing a white arrow to indicate that you may use this lane, or a red cross indicating that you may not use this lane because it is for traffic coming the other way. They were to enable the direction of traffic in some lanes to be varied according to the time of day (e.g. going towards the town or city centre in the morning peak and away from it in the evening peak).
Until about two or three years ago there was a tidal flow system on Queens Road, just south of Sheffield city centre, which I think had been in operation since about the late 1980s or early '90s but has now been replaced by a more state-of-the-art traffic management system. I seem to recall that there also used to be such a tidal flow system on the Mancunian Way or at least one of the major roads near Manchester Piccadilly station.
I don't think they were ever common though, the only other road I recall ever seeing them on was a single carriageway 3 lane road in Cardiff around 20 years ago.