Mobile phones are far more likely to distract drivers than passengers – even if they are wearing hands-free kits.

According to research from the US, passengers can actually be helpful to concentration by acting as a second pair of eyes.

The investigation, conducted by the University of Utah and published in the of Experimental Psychology: Applied, shows that reaction can makes younger drivers react at the same pace as old age pensioners or the legally drunk (but presumably not drunk OAPs).

"The passenger adds a second set of eyes, and helps the driver navigate and reminds them where to go," Strayer said in a statement.

Facemail meeting?

"When you take a look at the data, it turns out that a driver conversing with a passenger is not as impaired a driver talking on a cell phone," he added.

"The difference between a cell phone conversation and passenger conversation is due to the fact that the passenger is in the vehicle and knows what the traffic conditions are like, and they help the driver by reminding them of where to take an exit and pointing out hazards."

So there you go – all the more reason to crank up the stereo and ignore the mobile whilst you are on your way home.