1 of 46© Boardworks Ltd 2007. 2 of 46© Boardworks Ltd 2007 Speed and safety Why are speed limits important?

1 of 46 © Boardworks Ltd 2007


Speed and safety

Why are speed limits important?


Why have speed limits?

Speed limits are an important part of road safety. They aim to prevent drivers from driving at speeds that are unsuitable and unsafe.

The speed limit of a particularroad depends on a range offactors, such as how straight or curved it is, and its location.

The faster a vehicle is driving, the longer it will take to stop – the overall distance this takes is the stopping distance.

stopping distance = thinking distance + braking distance


Stopping distances


alcohol

other drugs and some medicines

tirednessdistractions, such as

mobile phonesspeed

What affects thinking distance?

The thinking distance is the distance a vehicle travels in the time it takes for a driver to react to a situation and apply the brakes.

What factors will affect thinking distance?


weather

condition of tyres/brakes

What affects braking distance?

The braking distance is the distance a vehicle takes to stop once the driver has applied the brakes.

What factors will affect braking distance?

condition of roadspeed


Factors affecting stopping distances


How do speed cameras work?

There are several types of speed camera., They use different methods to calculate the speed of a vehicle.

Gatso speed cameras use radar to detect the speed of a vehicle, then take two photos (half a second apart) to provide visual evidence. Lines marked on the road indicate how far the vehicle has travelled in that time.

Truvelo speed cameras are activated by pressure detector cables in the road. The cables are 10 cm apart and a computer calculates how long it takes the vehicle to pass from one to another, and therefore the speed of the vehicle.


Speeding and speed cameras



Glossary (1/2)

acceleration – A measure of how an object’s velocity changes over time. It usually refers to an object that is speeding up.

braking distance – The distance it takes for a vehicle to stop once its brakes have been applied.

deceleration – Negative acceleration, i.e. slowing down.

non-uniform – Speed or acceleration that is constantly changing.

speed – A measure of how far an object moves in a given time.


Glossary (2/2)

stopping distance – The total distance it takes for a vehicle to stop, i.e. thinking distance plus braking distance.

thinking distance – The distance it takes for a driver to react to a situation and apply the brakes.

uniform – Speed or acceleration that is constant and unchanging.

velocity – A measure of the speed and direction of a moving object.


Anagrams


What does the graph show?


What does the graph show?


Multiple-choice quiz

Documents

1 of 46© Boardworks Ltd 2007. 2 of 46© Boardworks Ltd 2007 Speed and safety Why are speed limits important?