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A flat tyre never happens at a convenient moment. One minute you’re driving normally; the next, the steering feels heavy, you hear a rhythmic thump, and your stomach drops. Knowing what to do if you get a flat tyre (calmly and in the right order) keeps you safe and gets you moving again faster.

This guide walks you through it step by step: how to stop safely, when you should absolutely not attempt a change yourself, and why calling a mobile fitter is often the smarter call, especially as many modern cars no longer carry a spare at all. The UK driving test doesn’t cover any of this, so don’t feel caught out.

How to tell you’ve got a fat tyre

The car may pull to one side, the steering can feel heavy or vague, and you’ll often hear a thumping or rumbling through the wheel. If you notice any of these issues, don’t ignore them and don’t keep driving in the hope it settles. Driving on a flat ruins the tyre, can wreck the wheel rim, and badly affects how the car steers and stops. The sooner you react, the more likely the tyre can be repaired rather than replaced, and the safer you’ll be. Ease off the accelerator gently and start planning where to stop.

Step 1: Slow down and pull over safely

Resist the urge to brake hard or swerve. A sudden input on a damaged tyre can pull the car off line, especially if it’s a front tyre. Instead, lift off the accelerator and let the car slow gradually while you keep a firm, steady grip on the wheel.

Indicate early and look for the safest place to stop. You want firm, level ground, well away from moving traffic, and ideally not on a blind bend or the brow of a hill. A car park, side road, or driveway is far better than a roadside verge. On an A-road, get as far from the live lane as you can.

Don’t fixate on stopping instantly; a few extra seconds to reach a genuinely safe spot is worth it. The flat is already flat; a slightly longer roll won’t make it meaningfully worse.

Step 2: Switch on hazards and get everyone safe

Once stopped, put your hazard warning lights on straight away so other drivers can see you. If it’s dark or visibility is poor, turn on your sidelights too.

Apply the handbrake and, if you’re on any kind of incline or near traffic, turn the steering so the wheels point away from the road. Get any passengers out of the vehicle through the doors on the side away from traffic, and keep children and pets under control. Put on a hi-vis vest if you have one.

Then take a breath and assess honestly: is it genuinely safe for you to change this tyre here? The Highway Code is clear: only change a tyre if you can do so without putting yourself or others at risk. If there’s any doubt, call for help instead.

When NOT to change it yourself: The Motorway Rule

This is the most important section, so read it even if you skim the rest. Never attempt to change a tyre on a motorway hard shoulder. The AA and National Highways are unambiguous: no roadside repair, however quick, is worth the risk with traffic passing at 70mph just feet away.

If you know nothing else about what to do if you get a flat tyre, National Highways advises a simple sequence often summed up as “go left”:

1. Get left. Leave at the next exit or pull into a service area if you can. If not, move onto the hard shoulder and stop as far to the left as possible.
2. Get out and behind. Switch on hazards, leave the car through the left-hand doors, and get everyone behind the safety barrier. 
3. Get help. Call National Highways on 0300 123 5000, then your breakdown provider, using the free emergency phones or your mobile.

Changing the tyre yourself (only if it’s truly safe)

If you’re somewhere safe, a quiet driveway, car park, or level side road in daylight, and you have the right kit, changing the wheel is straightforward:

1. Loosen the wheel nuts slightly before jacking, using the brace (and your locking wheel nut key if fitted).
2. Position the jack at the manufacturer’s jacking point and raise the car until the flat is just off the ground.
3. Fully remove the nuts, swap the flat for the spare, then hand-tighten the nuts.
4. Lower the car, then tighten the nuts firmly in a diagonal (star) pattern.

If your spare is a narrow “space-saver”, remember it’s a temporary fix only: most are limited to around 50mph and a short distance, so head straight to a garage for a proper replacement.

The reality: many modern cars have no spare

Here’s what catches a lot of drivers out. To save weight and boot space, a large share of new cars come with no spare wheel at all, just a tyre sealant and inflation kit. If that’s you, there’s no wheel to swap.

A sealant kit can temporarily seal a small tread puncture and reinflate the tyre enough to reach help. But it won’t fix a sidewall split, a large hole, or a tyre that’s already shredded, and once the canister is used, it needs replacing. Run-flat tyres buy you a bit more leeway, typically around 50 miles at up to 50mph, but no further.

Final Thoughts

A flat tyre on motorway is stressful, but the right response is calm and ordered: slow down gently, stop somewhere safe, switch on your hazards, and get everyone clear of traffic. Only change it yourself if you’re certain it’s safe, and never on a motorway hard shoulder.

If you’ve no spare, the sealant won’t hold, or you’d rather not risk it, we can come to you. Call our mobile team for a fast replacement if you don’t know what to do if you get a flat tyre, and we’ll get you safely back on the road.

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