Mirrors, Blind Spots and the MSM Routine

A lane change is you sliding a tonne and a half of metal into space you can't fully see. So you look before you move it, every time, in a fixed order. Get that order automatic and half of good driving runs itself.

MSM is Mirror, Signal, Manoeuvre, the sequence that sits under nearly everything you do on the road. It sounds like a slogan and people treat it like one, rhyming it off while doing none of it. The routine only works when each step means something. A mirror you didn't read is worse than no mirror, because now you think you looked.

Mirror: read it, don't glance at it

Before you change speed or position, you check your mirrors, and checking means taking in the information, not flicking your eyes at the glass out of habit. Centre mirror for what's directly behind, door mirror for the side you're moving toward. You want to know what's there, how fast it's coming, and whether your plan still works. When did you last check a mirror because you wanted the information rather than because the routine told you to?

Signal: tell people in time, or don't bother

The signal tells everyone else what you're about to do. It only helps if it comes early enough to be useful and only if you actually mean to do the thing. A signal flicked on as you're already turning tells nobody anything. A signal you leave on after the turn is a lie you're telling the car behind. Signal in good time, then follow through.

Manoeuvre: only once the first two say it's safe

The manoeuvre, the actual move, comes last, and only when the mirror and the signal have earned it. If the mirror showed a car flying up the outside, the manoeuvre waits. The whole point of the order is that you've gathered the information and warned the world before you commit. Do it in that order and you rarely get a surprise.

The blind spot the mirrors don't show

Here's the bit that catches people out and hurts them. Your mirrors do not show everything. There's a blind spot over each shoulder, big enough to hide a whole car or a cyclist, and no mirror covers it. Before you move off, before you change lane, you take a quick look over the shoulder to check it. A learner who moves off on the mirror alone, without the shoulder check, has missed the cyclist filtering up the inside. The tester marks it hard, and the road marks it harder.

Make it a reflex, not a recital

Done right, MSM stops being three steps you list and becomes one smooth thing your hands and eyes do on their own. That's the goal: not remembering the routine, but no longer being able to move the car without it.

Mirrors and blind spots are one piece of the bigger skill. For how they fit with where you actually place the car, here's observation and road positioning explained. Mirror, signal, manoeuvre, once, right, and the same every time. Then check the shoulder anyway, because no glass covers it.