Speed & stopping distances
Speed limits and the key rules of thumb
Your speed must fit
You may only drive so fast that you always stay in control (§ 3 StVO). Adapt your speed to road, traffic, visibility, weather, your abilities, vehicle and load. Speed limits are maximums – not targets. But without good reason, you must not drive so slowly that you hold up the flow of traffic.
Speed limits for cars
- In towns: 50 km/h
- Outside towns: 100 km/h
- Autobahn: no general limit, advisory speed 130 km/h
- With a trailer: 80 km/h (100 km/h with Tempo‑100 approval)
- Visibility under 50 m due to fog, snow, rain: max. 50 km/h
- With snow chains: max. 50 km/h
- Traffic‑calmed area: walking speed (approx. 4–7 km/h)
Outside towns: when doesn't 100 apply?
The general 100 km/h limit does not apply on roads with physically separated carriageways (e.g. a central crash barrier) or with at least two marked lanes in each direction. There – as on the Autobahn – the advisory speed of 130 km/h applies, unless a sign says otherwise.
The rules of thumb
Reaction distance = (speed ÷ 10) × 3
Braking distance = (speed ÷ 10) × (speed ÷ 10)
Emergency braking: braking distance ÷ 2
Stopping distance = reaction + braking distance
Example 50 km/h: 15 m + 25 m = 40 m stopping distance.
Stopping distance calculator
Move the slider and watch reaction and braking distance grow. Try 30, 50 and 100 km/h – and compare normal braking with emergency braking.
Educational rules of thumb, not a measurement of a vehicle.
Twice as fast = four times the braking distance
- 30 km/h: 9 m braking distance
- 60 km/h: 36 m braking distance
- 100 km/h: 100 m braking distance
- Where 30 km/h stops in time, 50 km/h is still barely slowed
- A crash at 50 km/h is like falling from about 10 m
Narrow roads: half the visible distance
If the road is so narrow that oncoming traffic could be endangered, you must be able to stop within half the distance you can see (§ 3 (1) StVO). The reason: the oncoming driver needs their stopping distance too.
Remember: being ready to brake saves metres
A reaction time of about one second is not fixed: fatigue, distraction and alcohol lengthen it considerably. If you already hover your foot over the brake in unclear situations, you shorten the reaction distance – often by the decisive metres.
Using the rule of thumb, how long is the stopping distance at 70 km/h with normal braking?
- 49 m
- 70 m
- 91 m
Check answer
70 m
Reaction distance 7 × 3 = 21 m, braking distance 7 × 7 = 49 m, total 70 m.
You double your speed. What happens to the braking distance?
- It doubles
- It quadruples
- It stays the same if the car has ABS
Check answer
It quadruples
Braking distance grows with the square of speed: double the speed, four times the distance. ABS keeps you able to steer but doesn't generally shorten the distance.
Practise emergency braking
Brake as hard as possible from 30 km/h – just like in the exam. Feel how short the distance is with full braking force.
This specific scenario is not implemented in the web edition yet. gfa_emergency_brake