Experiments show that drivers react more slowly when indicator lights are positioned nearer the centre of the car . . . rather than when they are fitted close to the outside edges of the body.

Experts say the reaction delay could cost other road users vital seconds when assessing which way the indicating car is going to turn.

Trials with student drivers showed they responded fastest to indicator lights that are closest to the car's front corners, as in the case of a Nissan Micra used as an example in the test.

But clusters with inside indicators, such as those in the old-shape Ford Mondeo, leave other drivers guessing for a vital moment or two longer.

The studies were carried out at the University of Wales under a team led by Dr Andrew Bayliss.