Mirrors, signal, manoeuvre

By the end of this topic you can

• You can use the MSM routine in the right order every time you change speed or direction.
• You can check the correct mirrors for the manoeuvre you are about to make.
• You can decide whether a signal is needed and give it at a sensible time.
• You can break the manoeuvre down into position, speed and look.
• You can include a blind-spot check when your mirrors cannot show you everything.

What you need to know and understand

• The Highway Code says to use your mirrors often and in good time, before signalling, changing direction or changing speed.
• Mirrors have blind spots, so a look over your shoulder is sometimes needed as well.
• A signal does not give you priority. It only tells others what you intend to do.
• Only signal if it would help or warn another road user, including pedestrians and cyclists.
• Brake lights also act as a signal, so check your interior mirror before slowing.
• Many instructors split the manoeuvre stage into position, speed and look (PSL).

The routine, step by step

Use the full routine well before the point where you act. Rushing it close to a junction leaves no time to react to what your checks show.

1. Mirrors: check the interior mirror, then the door mirror on the side you are moving to. Ask yourself what is behind and how close it is.
2. Signal: if anyone could benefit, signal clearly and in good time. Make sure it cannot be mistaken for another meaning.
3. Position: move smoothly to the correct place on the road for what you are doing.
4. Speed: brake or change gear so you arrive at the right speed, in the right gear.
5. Look: take effective observation into the new road or lane, then decide whether it is safe to go.

Which mirror, and when

Turning left, the interior and left door mirror matter most, because cyclists and motorcyclists can come up on your inside. Turning right or moving out, the interior and right door mirror tell you about anyone overtaking you. Before slowing down or stopping, the interior mirror tells you how close the vehicle behind is, so you can brake earlier and more gently if needed.

A quick sideways glance covers the blind spot, the area beside and just behind you that mirrors miss. Use it when moving off, changing lanes or when a cyclist could be alongside.

Acting on what you see

Checking your mirrors is only useful if you respond to what is there. If a car is close behind, slow down earlier. If a cyclist is coming up on your left, wait before you turn. If someone is already overtaking, delay your move out.

MSM is not a fixed script that ends at the signal. Keep checking as the situation changes, and be ready to cancel or delay your plan.

• Do: check mirrors before signalling, so the signal is right for the traffic around you.
• Do: cancel your indicator after the manoeuvre.
• Do not: signal and move at the same moment, giving others no warning.
• Do not: glance at a mirror without taking in what it shows.

Common mistakes

• Signalling before checking mirrors. Always look first so your signal suits the traffic behind you.
• Checking mirrors too late, right at the junction. Start the routine early enough to act on it.
• Forgetting the interior mirror before braking. A quick look tells you how firmly it is safe to slow.
• Leaving out the blind-spot check when moving off or changing lanes. Mirrors do not show everything.
• Looking but not responding. If your check shows a hazard, change your plan.

Test yourself: Mirrors, signal, manoeuvre

Answer each question, then read the explanation. Questions come in a random order each time.

Go deeper

• Mirror Signal Manoeuvre