Interesting paper on In-Car GPS Navigation: Engagement with and Disengagement from the Environment.
In a way it confirms what I have already suspected, that GPS serves as yet another distraction for the driver (along with mobile phones, etc) from doing the one thing that is most important at the time: paying attention to traffic and driving.
One of the findings is that people under the influence of GPS no longer pay attention to landmarks as a way of orienting themselves and finding locations. Nope, just blindly listen and follow whatever the GPS tells you. Cases of people getting horribly lost doing this are all over the internet. Reminds me of an experiment that was done back in the 80s that showed that people would rely on the results of a calculator that was programed to give the wrong answer even when they knew it was wrong because, well, of course the ‘machine’ knew better!
And I hope you have never had the unsettling experience of riding with someone who spends more time looking at the GPS screen than out the windshield. It is almost like they think the GPS is some video game in which they are driving a car rather than actually driving the car in the real world.