You pass a triangular warning sign showing a hazard symbol, with a rectangular white plate fixed underneath it reading '400 yds'. What does this plate tell you?
- That the warning only remains valid for the next 400 yards, after which the road returns to normal with no further indication needed
- That the advisory speed limit through the hazard is 400 yards divided by the posted speed, giving a target speed in mph
- That the hazard itself begins about 400 yards further along the road from where the sign is standing, not at the sign itself
- That you must maintain a following distance of at least 400 yards behind the vehicle in front while the warning applies
Why C? And why not the others?
Correct answer: C. That the hazard itself begins about 400 yards further along the road from where the sign is standing, not at the sign itself
A rectangular plate mounted beneath a warning triangle states the distance from the sign to the actual start of the hazard, so a driver knows the danger is not immediately at the post but a further stretch ahead, giving time to judge when to slow or position the car. The option inventing a formula that derives an advisory speed from the distance and the posted limit makes up a calculation that UK traffic signs do not use; a distance plate states distance, not a speed to compute. The option claiming the warning simply expires after that distance and the road returns to normal misreads the plate's purpose: it marks how far ahead the hazard starts, not how long a temporary warning remains in force, and hazards such as bends or junctions do not carry an automatic 'all clear' after a fixed distance. The option treating the figure as a required following gap confuses a hazard-distance plate with driving guidance about following distance, which is governed by separate Highway Code advice about reaction time and stopping distance rather than by the wording on a warning sign's plate.
Source: GOV.UK, The Highway Code — Traffic signs (warning signs and supplementary plates); DfT Know Your Traffic Signs