Backseat drivers - we've all complained about them.
First there's "you're driving too slowly", then it's "you're driving too fast" or there's the old favourite, "we're late ... and now we're going to be later because you took the wrong turn".
Now a study has revealed that those co-drivers can be useful and can even help prevent serious accidents.
Samuel Charlton is Professor of Psychology at the University of Waikato and is a co-author of research for the Automobile Association.
