allowed car cars drive driving overtake overtaking road roads sign traffic danger forbidden warning not pass passing pole post posts prohibition red round signpost signposts signs sundtraffic yellow advice advising alert appropriate-behavior appropriate-behaviour be-prepared-to-stop black care caution concern dangerous directions hazard information informing limited-access motorcars no-overtaking no-passing readiness ready risk risks risky road-sign roadwork safety slow vehicles warning-sign white workers workmen board overtakin prohibited street