Clearman, Brian2007-06-142007-06-142000https://hdl.handle.net/1794/4263325 p.1585524 bytesapplication/pdfen-USRailroads -- Signaling -- DatabasesTransportation Markings Database: Railway Signals, Signs, Marks, MarkersTransportation Markings Database: Additional Studies: Railway Signals, Signs, Marks & MarkersDatabase of Transportation-Marking Phenomena: Railway Signals, Signs, Marks & MarkersRailway Signals, Signs, Marks, MarkersBook