Stopping Distance

Definition

• Stopping distance: Minimum distance required to stop a vehicle in an emergency.
• Total stopping distance = Thinking distance + Braking distance.

Components of Stopping Distance

Thinking Distance

• Definition: Distance the car travels during the driver's reaction time (time between seeing the hazard and applying brakes).
• Factors affecting thinking distance:
  • Speed of the vehicle: Faster speed increases thinking distance.
  • Reaction time: Affected by alertness; increased by factors like tiredness, alcohol, drugs, or distraction.

Braking Distance

• Definition: Distance taken to stop under the braking force once brakes are applied.
• Factors affecting braking distance:
  • Speed and mass of vehicle: Increase in speed/mass increases kinetic energy to be reduced to zero.
  • Condition and quality of brakes: Worn/faulty brakes reduce braking force.
  • Traction between car and road:
    • Wet or icy roads decrease friction, increasing stopping distance.
    • Condition of tyres:
      • Bold tyres (no tread) reduce grip on road.

Impact of Speed on Stopping Distance

• Illustration with diagrams:
  • Diagrams show cars traveling at different speeds with sections for thinking and braking distances.
• Key observations:
  • Thinking distance increases proportionally with speed.
  • Braking distance increases more rapidly:
    • Doubling speed increases braking distance four-fold.
    • Tripling speed increases braking distance nine-fold.
• Graphical representation:
  • Total stopping distance vs. speed graph is not a straight line.
  • Steeper graph as speed increases, indicating increased stopping distance.

Conclusion

• Take-home message: Higher speeds significantly increase the stopping distance.
• Importance of understanding stopping distances for safe driving.