blue city crossing man pedestrian road road roads roadsign sign signs street town traffic urban walk warning cityscape post pylon street car tram tramway animal beware danger drive safety security sheep travel vehicle yellow digger excavator 70 car cars information limited speed driving forbidden overtake overtaking blur Calton Edinburgh hill scotland trams transport advice alert announcement appropriate-behavior appropriate-behaviour be-careful black care careful caution communicating communication concern dangerous informing lookout observant pedestrians red risk risks risky road-sign share sharing speed-reduction stop street-sign traffic-flow walkers walking warning-sign watch watch-out communicate denied law legal no-standing not-allowed not-permitted park permission-denied prohibited prohibition refusal restricted restriction restrictions road-safety road-side sky unacceptable vehicles verge white pedestrian plain roadsigns townurban zebra