Lights out!
Reaction test: how fast do you react?
The test takes a few seconds and shows why keeping your distance on the road matters so much.
Tap the panel or press the space bar.
Ready? Tap Start.
Best time: –
Racing drivers react to start lights in around 0.2 s. On the road, you reckon with 1 s. That's almost 14 metres at 50 km/h.
What the test measures
It measures the time between the lights going out and your tap. In the test, you know something is about to happen. On the road you don't. That's why driving schools work with a reaction time of around one second.
Reaction, braking and stopping distance
You'll learn these rules of thumb in theory lessons:
- Reaction distance in metres = (speed ÷ 10) × 3
- Braking distance in metres = (speed ÷ 10) × (speed ÷ 10)
- Stopping distance = reaction distance + braking distance
| Speed | Reaction distance | Braking distance | Stopping distance |
|---|---|---|---|
| 30 km/h | 9 m | 9 m | 18 m |
| 50 km/h | 15 m | 25 m | 40 m |
| 100 km/h | 30 m | 100 m | 130 m |
So what does your result mean?
A good score doesn't mean you drive safely. Tiredness, distraction and alcohol slow every reaction down. Look at your phone for two seconds at 50 km/h and you'll drive almost 28 metres blind.
Want to learn it properly?
Theory on Mondays, Tuesdays and Wednesdays, driving lessons by arrangement.