Safe following distance: criteria and special cases

There is no single distance suitable for every situation. Consider the speeds of both vehicles, reaction time, traffic, road gradient and alignment, weather, vehicle type and condition, brakes, tyres and load. Any factor that increases perception, reaction or braking distance requires a larger margin. Keep at least 20 metres behind operating snowploughs and salt spreaders. On non-urban roads with one lane in each direction, goods vehicles over 3.5 tonnes that are subject to a no-overtaking restriction must keep at least 100 metres apart.