Can anyone share any information on these types of bridge signs? I couldn't find much on-line,thanks. Dimensions are 18" tall x 48" wide x 3/4" thick and weighs 75 lbs and is solid cast iron. First one of these I have come across. I am not sure if I am listing in the correct category so please excuse me if I have made a mistake. My father who is 80 thinks it may have come off of a old local railroad bridge.