The recent study has found that it takes an average of 1.5 seconds to spot a hazard and apply the brakes - more than double the 0.67 seconds used in the Department for Transport's book.
This means the stopping distance for a car travelling at 20mph is 19 metres - seven metres more than that specified in the Highway Code. At 40mph, it is 51 metres - 15 metres more; and at 70mph, it is 121 metres, which is 25 metres more than in the code.
Jason Wakeford, the spokesman for Brake, said: "These figures suggest stopping distances taught to new drivers in the Highway Code fall woefully short. 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."
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 distractions in the car, which extends this time, like using a mobile phone, could prove fatal."
RAC spokesman Rod Dennis said the new figures should be taken seriously - "From time to time, new evidence will come to light that means it is necessary to update the Highway Code and perhaps this is one such instance.
Brake is asking the Government to increase the stopping distances in the Highway Code, as a "matter of urgency."