A hazard is defined as any situation, which could involve you changing your speed, position or direction on the road.
A manoeuvre is defined as any actual change of direction or speed.
Before you consider either of the above you should use the Mirror Signal Position Speed Look routine.
Mirrors - check early to assess the speed and position of following traffic and to make sure it’s safe to carry out your intended action. Before moving to the left or turning left, check the interior mirror first followed by the left door mirror. Before moving to the right or turning right, check the interior mirror first followed by the right door mirror. Before speeding up or slowing down check all three mirrors.
Signal - consider giving a signal, the main ways in which we signal are indicators, brake lights and reversing lights. You don’t always have to give a signal and sometimes you may have to delay a signal because of the circumstances or the road layout.
Position - consider your positioning. Your position should give you the best possible view of the road ahead while maintaining adequate safety margins all around the vehicle. You don’t always have to change your positioning or sometimes you may have to delay your positioning because of circumstances out of your control. Your positioning on the road can also act as a signal, for example if safe taking up a position towards the centre of the road when you wish to pass parked cars is telling other road users you intend to pass the cars and not pull up on the left before them.
Speed - consider your speed. If a change of speed is required adjust in good time and consider your gear.
Look - The look phase spans the whole routine and involves you constantly scanning the road ahead, to the side and in your mirrors to assess the situation.
Key points to remember:
Starting the routine early allows you to make smooth unhurried progress.
You should consider all the phases of the routine in sequence, however you may not have to use every phase in a particular situation.
Hazards don’t come neatly one after the other, the routine can cover several hazards at the same time.
More detailed information can be found in Driving the essential skills and the Highway Code.