Stopping Distances - RoSPA's Pedestrian Injury Simulator

Facts : Speed

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Introduction

When a car is travelling at a high speed, a driver has less time to identify hazards and react to what is happening around them. It takes vehicles further to stop from higher speeds, and if there is a crash, the injuries will be more severe.

Speed increases both the thinking distance and the braking distance. A driver travelling at faster speeds will have covered more ground in between spotting a hazard and reacting to it. The simulator will give you an idea about how much longer thinking distances can be at higher speeds.

Speed limits are, therefore, set to help drivers understand the dangers of each road, and inform drivers of the legal maximum speed, above which the risks to the driver and other road users are too great to accept.

Facts and Statistics about Speed

Speeding and excessive speed causes thousands of serious accidents and injuries every year.

Excessive speed contributes to 24% of collisions in which someone is killed, 15% of crashes resulting in a serious injury and 14% of all injury collisions. In 2010, 241 people were killed in crashes involving someone exceeding the speed limit and a further 180 people died when someone was travelling too fast for the conditions.

Approximately two-thirds of all crashes in which people are killed or injured happen on roads with a speed limit of 30 mph or less.

Several studies have shown the extent to which speed increases the risk of injury, and this is also shown in the simulator.

The risk of a pedestrian who is hit by a car being killed increases slowly until impact speeds of around 30 mph. Above this speed, the risk increases rapidly, so that a pedestrian who is hit by a car travelling at between 30 mph and 40 mph is between 3.5 and 5.5 times more likely to be killed than if hit by a car travelling at below 30 mph.

The Simulator and Speed

The simulator allows you to experience and compare the potential effects of different speeds down a residential street, and show you how your choice of speed relates to a possible injury.

The simulator shows how speed increases both stopping and braking distances.

At different speeds, the thinking time that it takes a driver to respond to the hazard is the same. The distance increases, however, as the speed means that a greater distance is covered over the same time, and the simulator will show you the scale of this.

The braking distance is also increased due to speed, and a relatively small increase in speed increases the braking distance by a greater rate. If the speed is doubled then the braking distance is increased by four times.

These two factors mean that even a small increase in speed can extend the overall stopping distance by a large amount.

Remember, however, the driver always has time to react in the simulator so that you can see the effects of speed on distance. In the real world, a pedestrian may step out from a vehicle just in front of you.

Top Ten Tips to Avoid Speeding

One of the skills which drivers must have mastered to pass the driving test, is to ensure that they can drive within the speed limit at all times. However, sometimes drivers do find themselves above the speed limit accidentally, even though their intentions are to stay within it. This can be caused by many factors, such as the speed of other traffic, or inattention.

Although a driver may not intend to drive above the speed limit, drivers are responsible for the speeds that they actually drive. Whether by intent or accident, driving above the limit is illegal and can be very dangerous, especially in 30mph zones where even a couple of miles per hour extra may be the difference between a pedestrian walking away or suffering a serious injury.

Drivers who find themselves creeping over the limit need to find ways to watch their speed and stick below the limit. To help drivers, RoSPA has produced Top Ten Tips to Avoid Speeding which contains advice that may help you stay within the speed limit at all times.

. Top Ten Tips To Avoid Speeding
RoSPA's practical tips for drivers who find it difficult to stay within the speed limit.


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Produced with the support of the Department for Transport.
Produced with the support of the Department for Transport.
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