TORONTO - A Dutch study of the way drivers use navigation systems in cars has found that some systems on the market are so cluttered and difficult to use that they threaten driver safety.
The worst appear to be systems with overly detailed displays, especially those that try to render maps in natural colors or photo-realistic pictures. Those with multifunction buttons also are difficult to use, the researchers said.
The study was ordered by the Dutch government, which wants to issue a standard for such systems.
Wiel Janssen, a senior scientist at the TNO Human Factors Research Institute in the Netherlands, told a technical panel at last month's sixth World Congress on Intelligent Transport Systems that the study looked at five commercially available systems.
Janssen said the test began with a baseline definition of 'safe' driving activity that was finding and listening to traffic reports on a car radio.
After testing 72 drivers 23 to 45 years old, all with more than five years' driving experience, researchers found that navigation systems with high-contrast, artificial-color map displays caused the least distraction.
Navigation systems with movable, hand-held control units let drivers perform at or near the 'safe' level the study defined, that of driving while listening to traffic congestion reports.
'Several systems were less safe than the accepted standard. I have to be careful here - this doesn't mean they were unacceptable in an absolute sense,' Janssen said.
But he said it was a surprise to researchers that in an age of ergonomic design and human-factors studies, difficult-to-use equipment is still being installed in vehicles.
As a result of the study, the Dutch Transportation Ministry found the Philips Carin 520 and the Volvo/Mitsubishi RTI navigation systems met acceptable levels to use in the Netherlands.