Programming your satnav while driving is the most attention-absorbing – and dangerous – activity for modern drivers, a new experiment has concluded.

Road safety charity IAM RoadSmart teamed up with Carbuyer – an AutoExpress sister title – in order to carry out the tests.

British Formula 3 racing driver Jamie Chadwick joined AutoExpress consumer editor Joe Finnerty in an advanced driving simulator in order to pinpoint how driver concentration is impacted by a variety of distractions.

The pair were asked to undertake timed laps, alongside an exercise involving braking at a specific point.

The results were eye-opening.

Interacting with a sat nav resulted in slower lap times, while it caused racing driver Jamie to completely miss her braking point.

Tim Shallcross of IAM RoadSmart monitored the tests. He said: “The moral? Those warning screens about not entering details on the move are there for a reason – don’t ignore them.”

Texting behind the wheel came after sat nav use in terms of danger. Eating, drinking and talking to a passenger were also analysed.

Strikingly, Shallcross suggested that using a mobile behind the wheel meant that "the car was more or less out of control.”

By using a phone while driving a motorist became “a menace to other road users", said Shallcross.

And while talking to passengers is commonplace on our roads, it still acts as a distraction – which could reduce reaction times and ultimately put both driver and passenger(s) in peril.

“These results highlight just how important it is that drivers give their full attention to the road ahead," said Steve Fowler, editor of AutoExpress.

“We’ve seen the staggering numbers of people who are still using phones at the wheel, and these tests show how dangerous they can be – whether it’s texting, calling or programming the sat nav.

He added: “More work needs to be done to target those who still think it’s acceptable to use a phone while driving.”