Stopping Distances

35mph while using a phone during wet weather

You were using a mobile phone, driving at an excessive speed, and the road was wet, so you hit the pedestrian.

The excessive speed increased both your thinking distance and braking distance. The wet weather reduced your car's grip on the road, and increased your braking distance whilst the distraction of the mobile phone increased the time it took you to spot, and react to, the pedestrain. All three of these factors significantly increased your overall stopping distance.

Any of these three factors would have caused the vehicle to hit the pedestrian but all three in combination have resulted in a serious injury.

Thinking Distance
Braking Distance
Overall Stopping Distance

Injury: Yes, the car hit the pedestrian.

In this scenario, most pedestrians would be injured and only one in every ten would avoid a serious injury. Half of the accidents in these conditions would result in the pedestrian being killed.

Suggested Comparisons

  1. Speed increases both the thinking distance and braking distance, although the use of a mobile and the wet weather meant that in this instance, a lower speed would not have avoided the collision. You can re-run the simulator at a lower speed, without using a mobile phone use or wet weather, to see how much the stopping distance is decreased.
  2. Drinking alcohol also increases the thinking distance meaning that the driver takes longer to spot and react to the pedestrian. Re-run the simulator, and select alcoholic impairment instead of mobile phone use, to see how this changes the result.
  3. Wet weather increases braking distances. Re-run the simulator, and select dry weather, to see how this decreases the braking distance.

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