In normal conditions, what is the minimum following distance for a heavy vehicle?

• A. Three seconds
• B. Four seconds
• C. Six seconds
• D. Two seconds

Answer: (B)

Four seconds is the minimum following distance for a heavy vehicle in normal conditions. Heavier trucks have more mass and momentum, which means they need a longer stopping distance. Keeping a four-second gap gives you enough time to spot a hazard, react, and brake before you reach the vehicle ahead, even if it brakes suddenly. You can check this by picking a fixed point ahead and ensuring you pass it about four seconds after the lead vehicle does. If road conditions are poor—rain, snow, ice, or reduced visibility—increase the gap beyond four seconds to six seconds or more. Gaps shorter than four seconds leave little margin and raise the risk of a crash.