A driving reaction time test measures how quickly you brake after a hazard appears. Your result is turned into stopping distance at real road speeds. Even a fast reaction adds several metres, because the car keeps moving while you react.
From milliseconds to metres
Stopping distance has two parts. Thinking distance is how far you travel before your foot hits the brake. Braking distance is how far the car slides after that. At 100 km/h a car covers about 28 metres every second, so each tenth of a second matters.
Our table uses your average reaction and a firm stop on a dry road with good tyres. Wet roads, worn tyres and heavy loads make braking distance much longer.
Real roads are slower than this test
On screen you know a signal is coming. On the road a hazard is a surprise, and you must also move your foot from the accelerator. Studies of real drivers often find brake reactions between 0.7 and 1.5 seconds. The UK Highway Code uses about 0.67 seconds for its thinking distance charts.
Tiredness, phones and alcohol can stretch that time a lot. Use this test to understand the numbers, not to decide whether you are fit to drive.
How it works
- 01
Start driving
Tap to set off. The road moves and the traffic light stays green.
- 02
Brake for any hazard
Red light, braking car, pedestrian, animal or ball: tap or press Space at once. Braking for a decoy restarts that run.
- 03
Read your stopping distance
After three runs, see metres travelled at 50, 80 and 100 km/h.
Who uses this test
- Learner drivers studying thinking and braking distance
- Driving instructors showing why phones and driving do not mix
- Older drivers keeping an eye on their own reaction speed
- Road safety lessons in secondary schools
- Comparing a rested score with a late-night score
- Delivery and fleet drivers in a team safety talk
Frequently asked questions
What is a normal driving reaction time?
Most drivers take about 0.7 to 1.5 seconds to brake for a surprise hazard on a real road. A screen test is faster because you are expecting the signal. Use both numbers to understand the gap.
How is stopping distance calculated here?
Thinking distance is speed multiplied by your reaction time. Braking distance uses the speed squared divided by twice a firm braking rate of 7 m/s². The two are added for the total.
How much does a phone slow braking reaction time?
Research on texting and calls shows big delays, often adding half a second or more. At 80 km/h that is over 11 extra metres before braking starts.
Does this test show if I am safe to drive?
No. It is an educational game, not a medical or driving assessment. Talk to a doctor or a driving assessor if you have concerns.
Why does tiredness matter so much for drivers?
Lack of sleep slows reactions and causes lapses where you do not react at all. Studies link long hours awake to impairment similar to drinking alcohol.
How can I react faster while driving?
Look far ahead, keep a safe gap, avoid distractions and rest before long trips. Covering the brake in risky spots also cuts the time to stop.
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