Last month, the Department for Transport began a study into the safety of older tyres. With more than half a million classic cars on our roads, what might the implications be?

Historic vehicles such as ours cover tiny annual mileages as a whole. Kept as a fair weather conveyance, and driven from show to show, their tyres may stay on for far longer than the ten year cut-off date generally accepted by the rubber industry.

Against a rising trend of serious accidents caused by ‘illegal, defective or under inflated’ tyres, a six-year campaign to have older tyres examined finally began in March – after a six year campaign by a parent of a child killed by a 19 year old coach tyre which failed.

Roads Minister Jesse Norman announced the publicly-funded study, the first of its kind, was to be conducted by the Transport Research Laboratory, to provide “a fuller picture of the safety of tyres as they get older.”

Confined initially to buses and coaches – which have a legal minimum tread depth requirement of 1mm compared to the 1.6mm expected of cars – the 12-month survey could have long-lasting consequences on the historic vehicle movement.

Calls to examine the performance of older tyres are nothing new. Storied manufacturer Michelin proposed testing programme based on age and grip levels rather than tread depth; this, it argued last year, determines the safety margin of a tyre and the difference between avoiding an accident and causing one. Its data suggested a serious drop off in performance after tyres had seen out a decade.

Add in the effects of sunlight, loads carried and periods spent in indoor or outdoor storage off the road (typical for classic cars which, according to the National Historic Vehicle Survey 2016, cover just 1124 miles a year).

Jesse Norman added: “Existing guidance in this area has proven to be highly effective since 2012. “But we want to go further, to examine the issue of tyre ageing in detail.”

The DfT’s own statistical data set suggests that serious accidents from the aforementioned ‘illegal, defective or under-inflated’ tyres is heading upwards again; from a high of 146 incidents in 2014, contributing factors such as aged tyres caused 112 serious injuries in 2015, then rose again a year later with 120 people needing extensive rehabilitation.

Tyre age, of course, is not the only contributing factor, but it’s interesting that the DfT has chosen this emphasis for its research even before 2017’s tyre accident figures have been collected. Are we to see these statistics increase after MoT exemptions come into force?

Ben Field, managing director of Vintage Tyres, was pleased at Jesse Norman’s announcement.

“Tyres don’t improve with age, he commented. “On the surface, the rubber hardens and the tyre loses grip, particularly in the wet. Inside, the tyre can begin to delaminate. Delaminating may have no outer visual clues, but the integrity and safety of the tyre can be dramatically reduced. We don’t recommend fitting any tyre that’s more than eight years old, and any tyre over ten years old needs to be replaced, regardless of tread depth. We are, as a country, obsessed with tread depth as the key factor that decides if a tyre is safe or scrap.

Date codes have been moulded into tyres for decades now. It’s time they were checked as part the MoT. The fact that public service vehicles aren’t having their tyres torn off long before they reach old age by an effective testing system is an utter disgrace.”

We can but wait to see what the effects MoT exemptions will have on the DfT’s 12 month survey. While classic car enthusiasts will doubtless toe the line, the less scrupulous might abuse the lack of compulsory inspections. The continued presence of the part-worn tyre industry also worries some; although many firms are above board, a small minority sell tyres Trading Standards dubbed ‘lethal’. It wanted the whole second hand tyre trade shut down last year.

With no accurate statistics available for the age of tyres fitted to historic vehicles, Classics World will wait for the DfT’s findings with great interest.