But stop thinking so much just might be the best advice yet. Thinking apparently can be distractive enough to impair people's driving ability, says a new study appearing in the April issue of the Journal of Experimental Psychology. Nunes and his colleagues videotaped the eye movements of 12 people as they drove on two highways and two secondary roads. They then measured the size of the drivers' pupils and noted the amount of time they spent viewing specific objects and how often they checked the speedometer and the rearview and side mirrors. Driving ability is affected more by visualization tasks than verbal tasks, the researchers say.
Drivers also check their mirrors and the speedometer less often when distracted by visual tasks.
And, Nunes says, some drivers tend to drive faster when they're distracted. But if you have to picture something in your mind, he says, wait until you're not driving.