advice alert announcement appropriate-behavior appropriate-behaviour be-careful beware black care careful caution communicating communication concern danger dangerous directions informing Look looking lookout observant red risk risks safety sign signs warning warning-sign watch watch-out white cycling cyclists disability disabled path pathways pedestrians share sharing track walk walkers walking appropriate behavior appropriate behaviour be careful cars listen trams warning sign watch out yellow concrete ground-level alcohol banned consumption no-alcohol not-allowed not-permitted prohibited prohibition no-speeding park pedestrian-priority blue children kids slow slow-down slower traffic vehicles above aerial air air-industry air-travel airservices angles arial blades colored colors coloured colours conditions fine flight flying flyover height helicopter helicopters high looking-down observation patrol patrolling perspectives recon reconnaissance rotors security sky speed transport transportation travel traveling travelling views