Stopping Distance

• Stopping distance


  The minimum distance required to stop a vehicle in an emergency
• Total stopping distance


  Thinking distance + Braking distance
• Thinking distance


  The distance the car travels during the driver's reaction time, which is the time between the driver seeing the hazard and applying the brakes
• Factors affecting thinking distance

  • Speed of the vehicle
  • Reaction time
• Reaction time


  The time between the driver seeing the hazard and applying the brakes
• Factors decreasing alertness and increasing reaction time

  • Being tired
  • Being drunk
  • Being on drugs
  • Being distracted
• Braking distance


  The distance taken to stop under the braking force, once the brakes have been applied
• Factors affecting braking distance

  • Speed of the vehicle
  • Mass of the vehicle
  • Condition and quality of the brakes
  • Traction between the car and the road
  • Condition of the tyres
• As speed increases


  Braking distance increases more quickly than expected
• If speed doubles, braking distance increases four-fold
• If speed triples, braking distance increases nine-fold
• As speed increases


  Total stopping distance graph gets steeper
• Travelling fast in a car means it will take a lot longer to stop than expected