Stopping distances

• What is stopping distance?

  The minimum distance to stop a vehicle
• What is the formula for total stopping distance?

  Total stopping distance = thinking distance + braking distance
• What does thinking distance represent?

  The distance traveled during reaction time
• What two main factors affect thinking distance?

  Speed of the vehicle and reaction time
• How does speed affect thinking distance?

  Higher speed increases thinking distance
• What can increase a driver's reaction time?

  Being tired, drunk, or distracted
• What is braking distance?

  The distance taken to stop after braking
• What factors affect braking distance?

  Speed, mass, brake condition, and traction
• How does speed affect braking distance?

  Higher speed increases braking distance
• Why does braking distance increase more than expected with speed?

  Kinetic energy must be reduced to zero
• What happens if brakes are worn or faulty?

  They apply less pressure, slowing down less
• How does road condition affect stopping distance?

  Wet or icy roads reduce traction
• What is the effect of bald tires on stopping distance?

  They reduce grip on the road
• What is the relationship between speed and stopping distance?

  • Thinking distance increases proportionally with speed
  • Braking distance increases more quickly than expected
  • Doubling speed increases braking distance four-fold
  • Tripling speed increases braking distance nine-fold
• What does the graph of total stopping distance against speed look like?

  It gets steeper as speed increases
• What is the take-home message regarding speed and stopping distance?

  Higher speed means longer stopping time