Example:- if a child runs out in front of you! You will need quick reactions and good control of the car to stop promptly and safely. As this is an emergency then mirror checks will only delay your reactions therefore are not necessary - if you looked in your mirrors as often as you should then you would have an idea of following traffic anyway (i.e. mirrors checked for moving out when passing parked cars).
Poor Weather / Road Surface / Road Conditions
On a wet road it may take up to twice the braking distance to stop and much more on snow and ice. A good driver should not need to carry out too many emergency stops. If you look out for warning signs where pedestrians / children are more likely to be around then you are less likely to get caught out. 30mph may be the maximum in many built up areas but judge every road accordingly.
Are you driving at an appropriate speed?
If you hit a child at 40mph there is an 80% chance you will kill that child. 4 out of 5 will be killed. If you hit a child at 30mph there is an 80% chance the child will live but may be left with serious injuries. 4 out of 5 will live. If you hit a child at 20mph there is a likelihood of less serious injuries. So watch your speed as even a few mph can make a difference!
At 20mph your overall stopping distance would be around 40ft At 30mph your overall stopping distance is around 75ft (note: almost double that of 20mph!) At 40mph your overall stopping distance is around 120ft (note: almost three times greater than at 20mph)
Carrying out an emergency stop exercise
It is recommended that you practise stopping your car promptly under control, so that you know how to react if you ever had to stop your vehicle in an emergency situation for real. You may be asked to carry out a simulated emergency stop (controlled stop) on your driving test. Approximately one in three tests will include this exercise. Your examiner will ask you to pull over somewhere convenient and then warn you in advance that you will be given a signal for when you are to stop the car as if in an emergency situation.
You will need quick reactions when you get the signal - take your right foot off the accelerator pedal (gas) and apply foot brake firmly and progressively, then after a slight pause apply the clutch pedal with your left foot. Don't slam on the brake as this may lock up your wheels which would then cause the car to skid. Also try not to put the clutch down too soon, in order to allow the engine (whilst in gear) to assist with the braking, so you can stop sooner and are less likely to skid. As the weight will be thrown forward when you brake keep both hands firmly on the steering wheel to maintain control - take a deep breath when you have stopped, apply the hand brake and select neutral.
If it is your very first attempt it is a good idea to practise whilst your car is still stationary (a dry run!). This can help you get used to pivoting from the accelerator (gas) pedal to the brake pedal with your right foot and applying the clutch with your left foot before trying it on the move. A dry run will increase the likelihood of early success.
Observations before moving off
When you have stopped the car in an emergency you may be positioned more to the centre of the road, possibly to pass parked cars, therefore to check all areas that it is safe to move off again you will need to check over your left shoulder (blind spot), check all mirrors and over your right shoulder before moving off.