Factors affecting total stopping distance:
- looking at things - the faster the vehicle is travelling, the bigger braking force it will need to stop
- the faster your going, the greater stopping distance
- total stopping distance = the distance covered in the time between the driver first spotting the hazard and the vehicle coming to a complete stop
- reaction time = time between spotting the hazard and taking action
- the stopping distance = thinking distance + braking distance
1. Thinking Distance
- how FAST you're going - the faster you're going the gurther you'll go
- how DOPEY you are - affected by tiredness, drugs, alcohol and careless attitude
- bad visability and distractions are also a big factor - rain, radio, bright lights = driver doesnt notice hazard until closer. - Doesnt affect thinking distance, but start thinking about stopping near to the hazard = more likely to crash.
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- 2. Braking Distance
- how FAST you're going - faster travel, further it takes to stop
- how good the BRAKES are - worn or faulty are bad in situations they are needed the most
- how goot the TYRES are - minimum tread depth of 1.6mm to get rid of water in wet conditions. Leaves, diesel spills and rubbish on the road greatly increase braking distance, causing the car to skid.
- how good the GRIP is - dependent on 3 things...1. road surface, 2. weather, 3. tyres
- wet/icy roads are more slippy than dry roads.
- Typical stopping distances:
- 30mph = 14m Braking Distance + 9m Thinking Distance = 23m total stopping distance
- 50mph = 38m Braking Distance + 15m Thinking Distance = 53m total stopping distance
- 70mph = 75m Braking Distance + 21m Thinking Distance = 96m total stopping distance
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