cars caution children crossing drivers driving flag marker motor-cars orange pedestrians road roadside safety school school-crossing school-zone sign slow-down traffic vehicles walk walking warning attention beware blue careful child conduct control course danger drive guide happen highway industry kids law limit Look pedestrian people playground playing protection respect sidewalk slow street symbol teen transportation way zone advice alert announcement appropriate-behavior appropriate-behaviour area be-careful black care communicating communication concern dangerous directions informing looking lookout observance observant risk risks schools signs slower speed time times warning-sign watch watch-out red white communicate curbside direction drop-off entrance exit inform information message mobile mobility shadow shadows student students sunlight sunshine transport words yellow