It might be possible to repair a puncture at the roadside if: the puncture is within the central three-quarters of the tyre. the tyre's tread depth is over the legal minimum of 1.6mm. there is no evidence of a previous repair where the puncture exists. there is no side wall or shoulder damage to the tyre.
CAR & VAN TYRES
Ability to accelerate, steer and stop – Running your car with worn tyres makes it much more difficult to accelerate, steer and stop which puts you, your passengers and other road users at risk.
Fuel consumption – By increasing drag on the road, worn tyres will consume fuel inefficiently and cost you more to keep the car running.
Aquaplaning – Worn tyres decrease tread depth which means water is dispersed less effectively. In poor conditions this can lead to tyres losing contact with the road surface/aquaplaning.
Get them replaced, conveniently, by Michaels.