Total stopping distance is the sum of which distances?

• A. Perception distance, braking distance, and reaction distance
• B. Acceleration distance, friction distance, gravity distance
• C. Reaction distance, perception distance, and wind distance
• D. Perception distance, braking distance, and reaction distance

Answer: (A)

Total stopping distance is the distance your vehicle travels from the moment you first notice a hazard until you come to a stop. It combines three parts: perception distance (how far you travel from seeing the hazard to recognizing you need to react), reaction distance (how far you travel during the time it takes you to move from deciding to brake to actually applying the brakes), and braking distance (how far you travel after you begin braking until you stop). Add these together and you have the total stopping distance.

The correct set includes perception distance, braking distance, and reaction distance because all three contribute to the total. The other options bring in terms that aren’t standard parts of stopping distance, such as acceleration, wind, or gravity distances, which don’t describe what happens after you perceive a hazard and begin to stop.