The nagging voice of a satnav can drive motorists crazy but now academics claim it could also be impairing their ability to drive.
The results of an experiment show that people listening to complicated satnav instructions tend to drive faster, steer less steadily and become less likely to notice pedestrians stepping out on to the road.
Researchers say the study, which involved volunteers being set tasks by a computer mimicking satnav instructions, highlights the importance of the way verbal instructions are given.
Dr Polly Dalton, from the Department of Psychology at Royal Holloway, University of London, which carried out the study with colleagues from Lancaster University, said: "What is interesting is that people were able to follow one simple instruction without any significant impact on their driving.
"But as soon as they had to remember a compound instruction, consisting of two sequential directions, we began to notice a difference in their driving ability. A lot of effort has gone into designing visually-friendly satnav devices but our research highlights the importance of the way in which the auditory instructions are given."
Copyright Press Association 2012