How to read your result
This test measures simple reaction time: how fast you respond to a single, expected visual signal. Real driving adds perception and decision time - noticing the hazard, deciding what to do, and moving your foot - which is why studies put the full perception-reaction cycle for an unexpected event at around 1.5 seconds or more.
| Group | Typical time |
|---|---|
| Rested adult, simple reaction (this test) | 200–250 ms |
| Full perception-reaction, unexpected event while driving | ≈ 1.5 s or more |
| Older adults (60+) | typically slower on simple-reaction tests |
| Texting while driving | adds roughly a second or more before braking |
What that means at speed
At 60 mph your car covers about 88 feet every second. Every extra quarter-second of reaction time is another ~22 feet traveled before the brakes even start working. Try pairing your result with our stopping distance calculator to see the full picture.
Factors that slow reaction time
- Fatigue - studies link even moderate sleep loss to measurably slower responses.
- Alcohol and cannabis, at levels well below legal limits.
- Distraction - research by the AAA Foundation and others finds phone use adds substantial time before braking.
- Age - average reaction time gradually lengthens from middle age onward.
- Time of day - responses tend to be slowest in the early morning hours.
Retest at different times of day to see your own variation. A single session is a snapshot, not a diagnosis.