One sign that was seldom heeded was on a railway bridge crossing a main road in a town. The town was on a hill with 2 roads running parralel with the railway bridges at rightangles to the roads. The lower raod had plenty of room under the bridge but the higher road had 10' 3 metres clearance with the sign on the side of the bridge in lights 3 feet high. Never a week went by without some lorry trying to go under this low bridge. I sometimes had a drink in a pub a few yards away from the bridge and when a bang was heard a loud cry of laughter went up from all the regulars. On one occasion a refrigerated lorry full of frozen chickens hit the bridge at speed. The roof got sliced of spreading thousands of chickens on the road. Within minutes there was not one single chicken left on the road and chicken was for lunch the next day for a great many people.