— Cynics often dismiss in-car satellite navigation (satnav) systems as an expensive luxury bought by people with no sense of direction.
But new research suggests that drivers using in-car satnav systems not only take less time to reach their destination, they may drive more safely, too.
Engineers Wen-Chen Lee and Bor-Wen Cheng of the National Yunlin University of Science & Technology in Taiwan paid 16 drivers to use in-car satellite navigation systems in order to reach a variety of urban and rural destinations they had never travelled to before. They hired another 16 motorists who were asked to use paper maps to reach a similar set of mysterious destinations.
The team found that the satnav-assisted journeys were around 7% shorter in towns than map-guided ones, and 2% shorter on rural runs.
"Using a navigation system saves time and gasoline when driving in unfamiliar regions, especially in an urban environment," Lee says in a paper to be published in a forthcoming edition of the road safety journal Accident Analysis and Prevention.
There was a further finding of significance. The researchers attached sensors to each car to log how often a driver made a course correction. In other words, when they drove one way and then turned back on themselves after realising they had made a mistake.
They found that map users changed course more times per journey than satnav users. This leads them to conclude that satnavs "lead to superior car handling and so may be safer," because frequent course changes are regarded as a sign of driver frustration, which can lead to attention deficit, aggressive driving and accidents.
Lee says a satnav system's ability to relieve the driver's mental workload is important: "Satnav users could take to the road immediately without any additional mental workload other than initially loading the destination into the device."
'Read the signs'
Map users, by contrast, have to study the street plan before driving off. "And their mental workload continues throughout the journey," he notes.
"Used sensibly, satnavs are a positive development that makes it easier for drivers to navigate correctly" says Roger Vincent of the Royal Society for the Prevention of Accidents, based in Birmingham, UK.
"But there are risks that drivers using them need to be aware of," Vincent adds. "Satnavs don't necessarily have the correct information, and that's a risk when people rely on them too much. People have taken turns onto railway lines, for instance, or driven wide trucks down narrow lanes and blocked access to villages. Drivers still have to use their heads and read the signs."