Stopping Distances

• Stopping Distance - the sum of the thinking distance and the braking distance.
• Stopping distance is affected by the:

  • mass of vehicle
  • speed of vehicle
  • driver's reaction time
  • state of vehicle's brakes
  • state of the road
  • amount of friction between tyre and road surface
• A driver's reaction time may be affected by alcohol, drugs / medicines, tiredness or distractions e.g. phone
• Braking Distance - distance a vehicle travels from when the brakes are applied to when it stops.
• Thinking Distance - distance a vehicle travels from when the driver sees an obstacle to when the brakes are applied.
• Reaction Time - the time taken between a person detecting a stimulus and their response.
• Thinking distance can be affected by the speed of the vehicle and the driver's reaction time.
• 0.5 X Mass X Speed^2 = Kinetic Energy
• For a car to stop, all its kinetic energy must be transferred to the thermal store of the brakes.
• Braking Distance and Speed have a squared relationship