Fifth Gear presenter Vicki Butler-Henderson hosted a slot on the programme in July, which showed the dramatic effect of worn tyres on stopping performance which travelling at 50 mph.
The test compared a “well-shod” L-reg Ford Granada with an M-reg Ford Scorpio with just 1.6 mm of tread and set them off on a wet surface at 50 mph. The Granada then braked with the just legal Scorpio in close pursuit – the resulting accident was horrific. Butler-Henderson told viewers that this clearly illustrated the dangers of running on near legal tyres and called for a change in the law to 3mm.
Independent tests, carried out by the Tyre Industry and part sponsored by the NTDA showed that braking performance deteriorates significantly in wet conditions when tyre tread depth drops below 3mm.
Research at MIRA (formerly the Motor Industry Research Association) has found that tyres with a 3mm tread have a 25% better performance than those at 1.6mm (the legal minimum). In terms of stopping distance, this represents an extra 8 metres (25 feet) in wet conditions. In one test, when a tyre with a tread depth of 8mm was compared to one with only 1.6mm, the stopping distance increased by 13 metres (42.25 feet) – almost the length of an articulated truck.
Sources reports that the official line is not as strong as Vikki Butler-Henderson’s line, but rather 3mm tread would make a significant contribution to road safety.
