Highway Code ‘falls short’ on stopping distances

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 car 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 car lengths (11 metres, on the basis that the average cars 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 car lengths (25 metres) at 70mph.

Overall average stopping distances
Speed 20mph 30 mph 40 mph 50 mph 60 mph 70 mph
Brake/TRL study 19m 34m 51m 71m 95m 121m
Highway Code 12m 23m 36m 53m 73m 96m
Difference 7m 11m 15m 18m 22m 25m

“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 car 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 a car in an emergency is one of the most important lessons for new drivers.  Understanding true average thinking time reminds all drivers how far their car will travel before they begin to brake - as well as highlighting how any distraction in the car which extends this time, like using a mobile phone, could prove fatal."

Added: 23 August 2017

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