advice alert announcement appropriate-behavior appropriate-behaviour area be-careful beware black care careful caution children communicating communication concern danger dangerous directions informing Look looking lookout observance observant risk risks road safety school schools sign signs slow slow-down slower speed time times warning warning-sign watch watch-out zone aware awareness forklift listen moving moving-machinery rain rain-drops red trams work workplace yellow white crossing information pedestrians risky road-sign speed-reduction stop street-sign traffic traffic-flow walk walkers walking cars cautious conditions gravel road-conditions slippage vehicles colors colours communicate dangers drowning-danger lettering message restricted restriction restrictions river riverside signage symbols text water wet color coloration colored colorful colour coloured colourful hiking paths tracks walking-paths walking-tracks cliff cliffside deterioration fading-sign fall falling light shadows shapes shrubs sunlight textures trees slippery aged aging elderly old security seniors symbol