A tyre blowout at 70 mph is one of the most alarming things that can happen on the road. The car will suddenly pull hard to one side, the steering will feel heavy, and there may be a loud bang or rapid deflation. Your instinct will be to brake and steer sharply away from the affected side. That instinct is wrong, and it can make things much worse.
What to do in the first 3 seconds
- Grip the wheel firmly with both hands. The car will pull toward the blown tyre — resist it with steady pressure, not a sharp correction.
- Do not brake. Braking transfers weight forward, further destabilising the car on a deflated tyre. Keep your foot off the brake entirely.
- Hold your speed briefly. Counterintuitively, maintaining momentum briefly keeps the car more stable. The drag from the flat tyre will naturally slow you down.
Steering to safety
Once you have the car under control (this happens within a few seconds), ease off the accelerator gradually and let the car slow naturally. Signal and move toward the hard shoulder or a safe stopping area. Only apply gentle braking once your speed is below 30 mph or so.
Once stopped
- Get as far off the road as possible — ideally behind a barrier
- Turn on your hazard lights immediately
- If on a motorway, exit from the passenger side and move well away from the carriageway
- Call us — we’ll come to you with a replacement tyre
Why blowouts happen
- Under-inflation — the most common cause. Low pressure causes the tyre to flex excessively, generating heat that breaks down the internal structure.
- Overloading — exceeding the tyre’s load index, particularly in vans and SUVs
- Sidewall damage — a bulge or cut that weakens the structure
- Age — rubber hardens and cracks, usually after 10 years
- Pothole impact — common in North Wales where road surfaces can deteriorate quickly through winter
Prevention
Check tyre pressure monthly. Inspect for bulges, cuts and cracking regularly. Replace tyres before the legal 1.6mm limit — at 3mm in wet conditions your stopping distance is already significantly affected. If a tyre has had a significant impact, have it inspected even if it appears undamaged — internal damage isn’t always visible.
This is general guidance to help you decide what to do next — it is not a substitute for a professional inspection. If in doubt, don’t drive on it. Call us and we’ll come to you.