This document discusses stopping distances for cars and the factors that affect them. It explains that stopping distance is the total distance required to bring a vehicle to a complete stop and is the sum of the thinking distance and the braking distance. It provides examples of stopping distances at various speeds and lists factors that influence thinking distance like speed, visibility, and alertness as well as those that impact braking distance such as speed, vehicle mass, road conditions, and tire and brake condition.

1. Stopping distances for carsStopping distances for cars

2. Know your speed limits – fill in the missing speeds
?

3. Built up area

4. Single lane highway

5. Dual two-lane highway

6. Dual
carriageway is
ending

7. Expressway

8. Stopping distances

Thinking distance
is the distance a
car travels before
the brakes are
applied.
Braking distance is
the distance a car
travels whilst the
brakes are being
applied.
Stopping distance = thinking distance + braking distance
Stopping distance
Braking
distance
Thinking
distance
How long does it take a moving vehicle to stop?
The stopping
distance is the sum
of the thinking
distance and the
braking distance.

9. Braking distance
The distance the car travels during itsThe distance the car travels during its
deceleration, whilst the brakes aredeceleration, whilst the brakes are
being appliedbeing applied
The distance the car travels in the split
second between a hazard appearing and
the driver applying the brakes
Thinking distanceThinking distance

10. The total stopping distance = thinking
distance + breaking distance
30mph
9m + 14m = 6 car lengths
50mph
15m + 38m = 13 car lengths
70mph21m + 75m = 24 car lengths

11. Thinking distanceThinking distance
It is affected by 3 main things:
1. How fast you are going
2. Being wide awake – drugs, tiredness,
alcohol, carelessness and old age.
3. Visibility – rain, oncoming lights, fog
and the night.

12. Braking distance
It is affected by 4 main factors:
1. How fast you are going
2. The mass (or load) of the vehicle
3. If the car is poorly maintained – brakes
and tyres (groves in tyres – 1.6mm deep)
4. The grip of the road surface – on a wet
road you can skid twice as long

13. Why is this illegal?
How will this affect your stopping
distance?
Bald tyres
make
stopping
distances
shorter on
dry roads,
Why
A bald tyre
has more
contact on
the road and
therefore
more
friction!

14. What about aquaplaning ?
• On a wet road, tyre treads channel water
out from between the tyre and the road
Removing
the water
away from
the tyre and
the road

15. What about aquaplaning ?
• Bald tyres allow a thin layer of water to
stay between the tyre and the road,
reducing friction
Why do racing
drivers change
their tyres when it
is wet?

16. Can you match up the words with their
definitions?
Stopping distance
Friction
Thinking distance
Braking distance
One of forces the road exerts on
the tyres as the car is stopping.
The distance a car travels whilst
it is braking.
The distance a car travels
before the brakes are applied.
The sum of thinking distance
and the braking distance.

17. What factors affect braking and thinking distance?
Thinking distance Braking distance
Speed of car
Speed of car Speed of car
Road conditions
Road conditions
Drugs and alcohol
Drugs and alcohol
Tiredness
Tiredness
Medication
Medication
Condition of tyres
Condition of tyres
Condition of brakes
Condition of brakes

18. Stopping a car…
Braking
distance
Too much
alcohol
Thinking
distance
Tiredness
Too many
drugs
Wet roads
Driving too
fast
Tyres/brakes
worn out
Icy roads
Poor
visibility