A new survey has revealed that almost a fifth of UK drivers do not understand what tyre tread depth is.
A study on tyre knowledge from Blackcircles highlighted that 72% of drivers feel confident in their tyre knowledge. However, this was not shown in further results, with many not understanding tyre safety issues.
Results show that 19% of those asked were not able to explain what tyre tread depth means. In addition, 32% believe the legal limit for tyres is 2.5mm. This is 0.9mm higher than the actual 1.6mm requirement, although this mistake could actually prove much safer.
However, 49% of those asked did correctly give the correct tyre tread depth legal limit. This means that 81% know that tyres should be replaced before they get to that point.
Scotland leads in tyre tread depth knowledge
Breaking these results down by region, Blackcircles found that drivers in Glasgow are most likely to know the legal minimum tyre tread depth, with 59% responding correctly. This was followed by Belfast with 58%, while 57% of drivers in Edinburgh were also right in identifying the 1.6mm legal limit.
Manchester had the highest rate of respondents who answered ‘don’t know’, at 32%. Blackcircles suggests that, despite similar confidence levels to other cities, drivers there lack fundamental awareness of tyre safety basics.
The results suggest that, while many do seem to know the legal tyre tread depth limit, there are a worrying number that are still unaware of the basic tyre safety requirements. With tyres being the only contact point between a car and the road, it is crucial that those operating vehicles are aware of the safety implications when it comes to worn rubber.
On the DOT
When it comes to DOT numbers, which indicate the week and year of a tyre’s production, only 35% answered correctly as to what this indicated. This was far below the confidence levels reported by drivers, and highlighting a clear example of false confidence.
In addition, 27% gave an incorrect meaning, while 38% did not know about the DOT markings at all.
As rubber hardens over time, tyres have a five-year shelf life and a 10-year usage life. This means that even if the tyre tread depth is within legal limits, the tyre itself may still be unsafe.
This could be a problem for older drivers, who use their cars less. With this, tyres are unlikely to wear quickly, leading to the perception that they do not require replacement. However, the Blackcircles study found that 54% of over 65s did not know about the DOT markings, while 20% were mistaken over their meaning.
It was, however, the 55-64 age range that was worse, with 55% unaware, and 19% mistaken. Drivers aged 25-34 were most aware with 50% answering correctly, and just 18% not knowing the meaning at all.
What this means
The results reveal that drivers trust their knowledge more than the data supports, creating a consistent pattern of overconfidence throughout the survey.
High confidence paired with low accuracy suggests that many motorists may believe they are maintaining their tyres properly, when in reality, they are missing key safety indicators such as tyre tread depth and age.
“Drivers who assume the tyre tread depth legal minimum is higher, at 2.5mm may replace tyres earlier than needed, but those who don’t know at all may be at risk of driving illegally or having accidents without realising it,” commented Ray Kavanagh, Chief Executive Officer at Blackcircles.
“Meanwhile, low awareness over the DOT code matters, as tyre age can be a hidden safety factor. Rubber degrades over time, even when the tread looks acceptable, which can put drivers at risk.”
