blue box bridge calm city cityscape clear cross crossing curve dundee hill house houses locomotive over perspective rail river scotland sea shadow signal sky still Tay track tracks train water automobiles autos cars hiawatha highway light lrt minneapolis minnesota mn railroad rails railway street traffic vehicles clyde copyspace glasgow peaceful pedestrian road sunny sunshine suspension urban bridges car clouds connect long north peace brick cantilever coast Edinburgh estuary famous Forth grey iron landmark metal paint painting Queensferry red rocks shore span stone advice alert announcement appropriate-behavior appropriate-behaviour be-careful beware black care careful caution communicating communication concern danger dangerous directions informing listen Look looking lookout observant railway-crossing risk risks safety sign signs trains warning warning-sign watch watch-out white tower