5.6.12 Stopping Distance

Stopping Distance

Stopping distance refers to the total distance a vehicle travels to come to a complete stop. It consists of two components: thinking distance and braking distance.

Thinking Distance:

Thinking distance is the distance travelled by the vehicle during the driver's reaction time.

• It is the time it takes for the driver to perceive a hazard and react by applying the brakes.
• Factors that can affect thinking distance include the driver's alertness, distraction, and the speed of the vehicle.

Braking Distance:

Braking distance is the distance travelled by the vehicle while under the influence of the braking force.

• It is influenced by factors such as the vehicle's speed, the condition of the brakes, and the friction between the tires and the road surface.
• Higher speeds generally require longer braking distances.

Relationship between Speed and Stopping Distance

• The stopping distance of a vehicle is directly influenced by its speed.
• As the speed of the vehicle increases, the stopping distance also increases.
• The relationship between speed and stopping distance is not linear but follows a more exponential pattern.

Estimating Stopping Distance

To estimate the stopping distance of a vehicle, follow these steps:

1. Consider the range of typical speeds for that vehicle.
2. Take into account the impact of different speeds on both thinking distance and braking distance.
3. Think about how the driver's reaction time and braking force will vary with different speeds.
4. Estimate the total stopping distance by adding the thinking distance and the braking distance together.

Interpreting Graphs

When interpreting graphs showing the relationship between speed and stopping distance:

1. Look at the x-axis (horizontal) to identify the speeds of the vehicles.
2. Examine the y-axis (vertical) to determine the corresponding stopping distances.
3. Notice how the stopping distance increases as the speed of the vehicle increases.
4. Pay attention to the slope or steepness of the line on the graph, as it represents the rate at which stopping distance changes with speed.
5. Understand that these graphs highlight the importance of maintaining appropriate speeds for safe braking, as higher speeds require longer stopping distances.

Conclusion

Understanding the concept of stopping distance allows us to appreciate the importance of factors such as speed, reaction time, and braking efficiency in ensuring safe driving. By analysing and interpreting graphs, you can develop a better understanding of the relationship between speed and stopping distance.