Chapter 7 - Speed and Maintaining a Safe Following Distance

Question 1

What is the normal maximum speed in a built-in area?

Answer 1

The max speed limit speed is normally 50km/h, unless a sign indicates a different speed limit, e.g. 70km/h

Note - Obviously you may encounter specifc section in a built-up area where the speed limit is lower –> 30km/h zone and 15km/h on private premises/play street

Question 2

What are the normall speed limits on motorways, trunk roads and all other roads outside a built-up area?

Answer 2

Motorways - 130km/h

Trunk road - 100km/h

All other roads - 80km/h

Note - this is just a rule of thumb –> if signs/electronic board indicates something else you must take the given value as the max speed limit.

Question 3

Is the maximum speed on motorways always 130km/h?

Answer 3

The standard max speed is 130km/h

But…

In many places there is a lower maximum speed in force –> this is indicated by electronic/road signs.

Sometimes the lowering of max speed occurs for a specific time period –> e.g. during peak hours

Question 4

What is the max speed for microcars within and outside built-up areas?

Answer 4

Speed limit for microcars within and outside built-up areas is 45km/h

The same applies to motorised handicapped vehicles

Keep this in mind when approaching such vehicles

Question 5

What is the max speed on all roads outside built-up area when driving with a trailer or caravan?

Answer 5

80km/h

Note - if you maximum permitted mass of your trailer or caravan is below 3,500kg –> your speed limit on motorways and trunk roads is 90km/h

Question 6

What are recommended speed signs?

Answer 6

Recommended a certain speed –> if you drive at these speeds you will normally be fine

Question 7

Why is it important to stick to speed limits/recommended speed apart from safety?

Answer 7

Allows for smooth flow of traffic –> you might benefit from a green wave of traffic lights

Question 8

Important circumstances when you just be aware and adjust your speed?

Answer 8

1. Around schools –> children may cross roads unexpectedly
2. Weather conditions
3. Condition of the road –> not always in good repair
4. Level of fatigue
5. Unfamiliarity of the situation

Question 9

What should you do before slowing down?

Answer 9

Before slowing down, look in your mirrors to observe the distance between yourself and traffic behind you.

Question 10

Why is driving quicker not always a good idea?

Answer 10

In order to gain time you need to drive quick for a long period –> often not the case as there is traffic

Plus…

1. Higher petrol consumption
2. Greater risk of an accident

Question 11

What are the risk of driving at the maximum speed furing a long journey?

Answer 11

Misleading habituation

Drive too long on the motorway and then enter the built-up area –> you will have a tendency of driving too fast

Question 12

What does it mean to maintain a safe following distance? What is the rule of thumb?

Answer 12

Law states - you must drive in a way that allows you to stop within the distance of the road which is free ahead of you –> in practise this is not possible

General rule of thumb –> 2 second rule –> The distance between yourself and the vehicle infront should be equal to the distance you drive in two seconds.

Question 13

Easy way to calculate the rule of thumb for safe following distance?

Answer 13

Divide your speed in km/h by 2 and add 10%

Example when driving at 80km/h

80/2 = 40 + 10% = 44 metres

Question 14

Important thing to remember when someone pulls in front of you or overtaking?

Answer 14

Make sure you apply the two-second rule to ensure that the vehicles around aren’t too close

Question 15

Under what circumstances should you increase the safe-following distance?

Answer 15

1. When there is a risk of aquaplaning –> basically too much water on the road surface
2. Wintry conditions
3. Driving down a steep hill
4. Driving in fog
5. Driving a heavily loaded vehicle
6. You are tired

Question 16

What happens to the stopping distance if you increase your speed?

Answer 16

Greater your speed –> Greater the stopping distance

Effect is progressive

Double speed = Braking distance increases fourfold

Question 17

What two things make up the stopping distance?

Answer 17

Reaction time + Braking time = Stopping distance

Question 18

What is reaction time? What is the average reaction time? How do you calculate it?

Answer 18

Reaction time –> time between you realise that you need to brake and for you actually to apply the brake

Average reaction time = 1 second

Reaction time distace = half the distance of the two second rule.

Calculation

(Speed in Km/h / 2 + 10%) / 2

1. Speed divided by 2
2. From the answer obtained - calculate 10% and add
3. Divide by 2

Question 19

What is the definition of braking distance? What is the formula?

Answer 19

Braking distance = Distance you cover from the moment uou apply the brakes until you come to a standstill.

If your brakes are in good working oder you can use the following rule:

[(Speed in Km/h / 10) x (Speed in Km/h / 10)]/2 = Braking distance

Question 20

What is the stopping distance? How to calculate it?

Answer 20

The stopping distance is the distance you cover from the moment you become aware of a dangerous situation to the moment you have come to a complete standstill.

Stopping distance = Reaction time dis. + Braking distance