Before slowing or stopping your vehicle, what is something you must do?

Before slowing or stopping… — Use your mirrors

The answer options

Select a higher gear
Flash your headlights
Sound your horn
Use your mirrorsCorrect

Why the other options are wrong

“Select a higher gear” is a distractor. It does not meet the standard the question is testing, which use your mirrors does. Picking it in the real test costs a mark you cannot get back, and with a pass mark of 43 out of 50 you only have seven to spare.
“Flash your headlights” is a distractor. It does not meet the standard the question is testing, which use your mirrors does. Picking it in the real test costs a mark you cannot get back, and with a pass mark of 43 out of 50 you only have seven to spare.
“Sound your horn” is a distractor. It does not meet the standard the question is testing, which use your mirrors does. Picking it in the real test costs a mark you cannot get back, and with a pass mark of 43 out of 50 you only have seven to spare.

Why that is the answer

Always check your mirrors before changing your speed or direction, following the standard MSM routine advised in The Highway Code. Checking your mirrors before slowing down or stopping allows you to see what is happening behind you, such as a vehicle following too closely. You can then adjust your braking safely to avoid a rear-end collision. Flashing your lights or sounding your horn is unnecessary and could easily mislead other road users.

What alertness covers

· Mirror–signal–manoeuvre and when each mirror is checked
· Blind spots and life-saver shoulder checks
· Correct signalling, including when not to signal
· Tiredness, breaks on long journeys and the 15-minute rest rule

Mistakes learners repeat on this topic

· Signalling so early that other drivers act on the wrong junction
· Checking mirrors after starting a manoeuvre rather than before
· Opening a window as a cure for tiredness instead of stopping
· Answering a hands-free call and assuming it is a safe alternative

Instructor tip: If a question offers 'stop somewhere safe and rest' for a tiredness scenario, that is almost always the marked answer.

How this comes up in the real test

Questions from alertness appear throughout the 50-question multiple-choice section, and the wording changes between versions. Learn the rule rather than the sentence: the DVSA can ask the same point from the opposite direction, and a memorised answer falls over the moment the phrasing moves.

The pass mark is 43 out of 50, so seven wrong answers is your entire margin. If a whole category is shaky, run the topic practice below until you are getting every question right for the right reason, then go back to full mocks under the clock.

Practise Alertness Sit a full mock test