http://www.nytimes.com/2012/09/02/technology/gps-and-human-error-can-lead-drivers-astray-digital-domain.html?ref=technology "...Human error, as it turns out, was responsible for many of the problems that occurred. ...This was not the fault of the software developers or a map deficiency, but the driver nonetheless placed the blame on the object that was most handy: “These GPS things — it’s really confusing.” (“Ahh, shut up,” the passenger said.) ...IT’S important to remember that humans can take in only so much information at one time. Today’s systems provide drivers with copious information in visual form, in addition to audible instructions. But research suggests that voice instructions without the screen may actually be safer."
I was very surprised how many people took the voice instructions as literal instructions without considering the environment (traffic, traffic restrictions, design of car park, road design, entrance/exit designs etc).
