Speed limits, following distance and stopping
This domain mixes memorised limits with the arithmetic of stopping. Expect questions on the general limits, on zone signs, and on the distance you must keep at a given speed - the exam likes the half-speedometer rule and reaction-distance calculations.
Limits (unless a sign says otherwise)
- 50 km/h inside built-up areas.
- 80 km/h outside built-up areas.
- 100 km/h on expressways (Autostrasse).
- 120 km/h on motorways.
- 30 and 20 zones in residential areas; the limit ends only at the end-of-zone sign.
- Car with trailer: generally 80 km/h, 100 km/h only for an approved combination.
Following distance
A safe default is half the speedometer reading in metres: 80 km/h means about 40 m, 120 km/h about 60 m. That is roughly 1.8 seconds - the two-second rule gives the same answer. Double it in rain, at night, in tunnels, when following a lorry that blocks your view, or when the road is downhill.
Stopping distance
The exam splits it into reaction distance plus braking distance:
- Reaction distance = (speed ÷ 10) × 3 metres.
- Braking distance on dry asphalt = (speed ÷ 10)² metres.
- Wet road: roughly double the braking distance. Snow or ice: several times more.
Worked example
At 80 km/h: reaction distance = 8 × 3 = 24 m; braking distance = 8² = 64 m; total about 88 m on a dry road. In heavy rain the braking part becomes roughly 128 m, so the total is about 152 m - nearly twice as far. The 40 m following gap is right for dry conditions, but in that rain you should be closer to 80 m. Doubling speed from 40 to 80 km/h quadruples the braking distance, from 16 m to 64 m.
Traps that cost marks
- Quoting dry stopping distances for wet or icy roads.
- Believing ABS shortens the stopping distance on ice - it mainly preserves steering.
- Forgetting that a full load or a downhill gradient lengthens braking.
- Treating the end of a 30 zone as automatic at the next junction; it ends at the sign.
- Following a truck at the same gap as a car, although you cannot see past it.