Motorway tyre debris analysed – but is the conclusion misleading?

Posted on May 29th, 2018 by Rob Marshall

Motorway tyre debris analysed - but is the conclusion misleading? 

In what was, probably, the first study of its kind, Highways England staff provided over 1,035 piece of tyre debris from the M1, M6, M40, M5 and M42 motorways to technical experts at Bridgestone Tyres for analysis. A video on the survey can be viewed here.

Working together, their conclusion was:

‘Almost three quarters of motorway incidents related to tyre failure could be prevented, if drivers carry out simple checks, according to startling new research by Highways England and tyre company Bridgestone.’

It makes a great sound-bite but I am unsure if trotting-out the usual (but nonetheless sound and relevant) advice of regular tyre inspections is hiding another pertinent point about the state of English motorways, for which Highways England is responsible.

The data reveals that incorrect inflation accounted for 18% of failed tyres, a figure that jumps to 26%, when added to the ‘poor vehicle maintenance’ category. Yet, over half (56%) of the tyre damage was caused by road/yard debris but scant attention was paid to this finding.

 

The Elephant in the room

As 56% of tyres failed due to road/yard debris penetration and the tyres were collected from motorways, it appears reasonable to conclude that much of the debris originated from the motorways – a point that was agreed upon by a spokesperson from Claims Management and Adjustment Limited, which has called upon Highways England and its contractors openly in the past to review its debris collection policies in the interest of road safety, after noticing a rise in motorway debris-related claims.

We put it to Highways England that the conclusions of the joint-project are deceptive, because they aim to blame the public for poor vehicle maintenance, when the real reason is likely to be more debris being present on motorways that is not being cleared quickly enough by Highway England and its contractors.

In response, Highways England directed our comment to Bridgestone and told GEM that it would not be adding anything to the statement that the tyre company provided to us, which can be read in full below:

 

“We understand from Highways England that our UK motorways are the most maintained roads across our complete road network and that motorway road clearance is of a high priority for the company.

 

Road hazard was the main failure reason from our report and it’s true that objects can be picked up from all areas of our UK road network. However, as our UK motorway network is the most maintained of all our roads, then the assumption is that these objects are picked up either from the remaining road network or yards.

 

In addition, tyre penetrations are generally not instantaneous, as the object needs to drill into the tyre fully to achieve rapid tyre deflation. Obviously the more tread you have the longer this process takes, so tyres near 1.6mm (passenger car minimum tread depth) or 1.0 (commercial truck HGV minimum tread depth) are more susceptible to instant failure.”

 

From our tyre samples, drilling was evident within the tread compound, clearly demonstrating that the object(s) had been in situ for some time prior to tyre failure. Therefore, regular inspection of tyres and the removal of objects from the tread prior to full penetration would reduce the number of road hazard failures on our UK motorway network.

 

Incidentally, perhaps it is a coincidence that the first example of a real-world puncture in the UK on Bridgestone’s DriveGuard run-flat tyres was reported by us and had been caused by motorway debris that had not been cleared…