Highway code falls short on stopping distances

Brake, the road safety charity, is calling on the Government to increase stopping distances in its next update to the Highway Code because drivers' thinking time has been under-estimated.

Brake asked the Transport Research Laboratory to provide evidence on the time taken by drivers to perceive, recognise and react to emergency situations. TRL referred to academic literature and concluded that the average thinking time is 1.5 seconds − more than double the 0.67 seconds set out in the Highway Code.

This means that average total stopping distance − including thinking and braking distance − is an extra 2.75 vehicle lengths (11 metres, on the basis that the average vehicle is four metres long) at 30mph and an extra 3.75 car lengths (15 metres) at 40mph compared with the distances used in the Code. This difference rises to an additional 6.25 vehicle lengths (25 metres) at 70mph.

Overall average stopping distances

“These figures suggest that the stopping distances taught to new drivers in the Highway Code fall woefully short,” Brake spokesman Jason Wakeford said. “Even though braking technology has improved in recent years, the majority of the overall stopping distance at most speeds is actually made up of the time taken to perceive the hazard and react.

“The research shows that average thinking time is more than double that set out in the Highway Code. A true understanding of how long it takes to stop in an emergency is one of the most important lessons for new drivers. Understanding true average thinking time reminds all drivers how far their vehicle will travel before they begin to brake − as well as highlighting how any distraction in the vehicle which extends this time, like using a mobile phone, could prove fatal."