Although appearing to be a great idea, having the speedometer displayed on a car's windscreen is just plain dangerous, according to a University of Toronto study.
The windscreen technology is known Heads Up Displays (HUD). It was designed to prevent the need for drivers to divert their attention from the road to look down at a speedometer, but the Toronto study says it is dangerous because it actually divides attention between the HUD and the road.
Participants in the study headed by Ian Spence, a psychology professor, were given different windscreens to look through in a driving simulator. The results showed drivers with the HUD technology had too much information to absorb and “as a primary task becomes more demanding ... both tasks compete with and interfere with each other”.
Spence said another problem which was discovered during the study was that if other information other than the speedometer was added and displayed, it interfered with the drivers decision making processes and ability to respond because of immediate information overload.
The study said "competing warnings may be more dangerous than no warning at all”.
Although more sophisticated versions of HUDs are being developed for use in jet fighters, pilots receive intense training on how to use the technology and are also taught when to ignore the view outside and concentrate on HUD and vice versa.