The A55 North Wales Expressway is the main arterial road of North Wales, carrying around 40,000 vehicles per day along its dual carriageway between Chester and Holyhead. At typical speeds of 70mph, a tyre blowout on the A55 is a serious and potentially life-threatening emergency that requires a calm, practiced response.
What Causes a Blowout?
A blowout — a sudden and rapid deflation of a tyre — can occur for several reasons:
- Under-inflation — the most common cause. Under-inflated tyres generate excessive heat as the sidewall flexes more than designed, which can cause sudden failure
- Impact damage — striking a pothole, kerb or debris at speed can cause immediate structural failure of the tyre
- Overloading — carrying more weight than the tyre’s load rating allows
- Worn tyres — tyres approaching or beyond the legal tread limit have significantly reduced structural integrity
- Tyre age — rubber degrades over time, increasing the risk of sudden failure even with adequate tread depth
- Sharp objects — debris on the carriageway can cause sudden puncture that, at speed, feels like a blowout
What a Blowout Feels and Sounds Like
A rear tyre blowout typically produces a loud bang, followed by the rear of the vehicle pulling strongly to one side. A front tyre blowout is more dramatic — the steering will pull sharply toward the affected side and the vehicle will feel very unstable.
Your instinct will be to brake hard and swerve to compensate. This is the wrong response and can cause a serious accident.
The Correct Response to a Blowout on the A55
Step 1 — Do Not Brake Hard
Hard braking when a tyre has blown can cause the vehicle to spin or go out of control. Keep your foot off the brake initially and maintain a firm, steady grip on the steering wheel with both hands.
Step 2 — Steer Straight
Steer firmly in the direction you want to go, counteracting the pull caused by the failed tyre. The vehicle will want to pull toward the blown tyre — apply steady counter-steering pressure.
Step 3 — Ease Off the Accelerator
Gradually release the accelerator to allow the vehicle to decelerate naturally. Do not use the brakes until the vehicle has slowed significantly and is under control.
Step 4 — Signal and Move Left
Once the vehicle is under control and slowing, signal left and gradually move toward the nearside lane, then onto the hard shoulder or an emergency refuge area.
Step 5 — Do Not Stop on the Carriageway
Never stop on the A55 carriageway itself — not even briefly. Drive on the deflated tyre to reach the hard shoulder. The damage to the tyre is irrelevant compared to the danger of stopping in a live lane.
Step 6 — Get Out Safely
Once on the hard shoulder, exit via the left-hand passenger door. Do not stand between your vehicle and moving traffic. Move well clear of both the carriageway and the hard shoulder — climb the embankment or stand behind the barrier if possible. Switch on hazard lights immediately.
Step 7 — Call for Help
Call Mobi Tyre on 07768 491888 from behind the barrier. We cover all sections of the A55 from Queensferry to Holyhead and respond 24 hours a day. Give us your location — use the marker posts on the hard shoulder, which show your exact location on the carriageway.
A55 Emergency Locations
The A55 has emergency refuge areas (ERAs) at regular intervals — look for the orange SOS telephone symbols on blue signs. These are safer than the hard shoulder as they are set back from the carriageway. Emergency telephones connect directly to the Highways England or Traffic Wales control centre.
How to Prevent a Blowout on the A55
- Check tyre pressures monthly and before any long journey
- Inspect tyres regularly for cuts, bulges, cracks and embedded objects
- Replace tyres when tread reaches 3mm — do not wait for the 1.6mm legal minimum
- Replace tyres older than 5-6 years regardless of tread
- Avoid overloading your vehicle beyond its rated capacity
Mobile Tyre Service on the A55 — 24/7
If you suffer a tyre failure anywhere on the A55 or surrounding North Wales road network, call Mobi Tyre on 07768 491888. We cover the full length of the A55 from the Welsh border at Queensferry to Holyhead port, available 24 hours a day, 365 days a year.
