Definition
Safe following distance is the gap to keep behind the vehicle ahead to stop without crashing if it brakes hard. It depends on speed, road surface, reaction time and braking capacity.
Key facts
- The 2-second rule: pick a fixed point on the road; if you pass it before counting two seconds after the car ahead, you're too close.
- In rain or fog, double the rule to 4 seconds.
- Outside built-up areas, vehicles over 3,500 kg must keep at least 50 metres behind.
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