Motorway Overpasses .

[keithlbw]

On motorway overheads do the camera vans catch both directions or just the lanes they are above .

[sunny-dave]

Usually only the ones they are above - but they could have the cameras pointing either way ... or indeed be dummies.

Only the revenue raising traffic stasi know.

[Hopkirk]

They are probably on their tea break, but they just park there to be seen.

A bit like the empty police cars parked at petrol stations.