In-car navigation systems make trips shorter, safer and more environmentally-friendly, according to researchers in Taiwan.

Wen-Chen Lee and Bor-Wen Cheng of the National Yunlin University of Science and Technology asked 16 drivers to use satnav systems displaying suggested routes on a screen. Another 16 used paper maps to reach a range of destinations.

The satnav-aided journeys were around seven per cent shorter in distance than map-guided ones in towns, and two per cent shorter in rural areas. The researchers concluded that since satnav journeys are shorter, they use less petrol and are therefore kinder to the environment.

The study, which will be published in industry journal Accident Analysis & Prevention and is reported today by New Scientist, also found that paper map users changed course more times per journey than satnav users, increasing petrol consumption still further.

What's more, said Lee, satnav "leads to superior car handling and so may be safer".