The Highway Code should be updated because its stopping distances are woefully short and underestimate drivers' thinking time, campaigners say.

The charity Brake said that distractions in cars, such as using mobile phones, bad weather, dodgy tyres and less than perfect brakes would only slow stopping times further.

A study commissioned by Brake estimated that it takes an average of 1.5 seconds to spot a hazard and apply the brakes, more than double the figure of 0.67 seconds used in the Department for Transport's book.

The new study calculated that the stopping distance of a car travelling at 40 miles per hour is 51 metres, compared with the figure of 36 metres in the Highway Code.

This is the equivalent of an extra 3.75 car lengths and Brake urged the Government to increase stopping distances in the book "as a matter of urgency".