Satellite navigation systems (satnavs) for cars, in which computer voices announce directions as you drive, save fuel and promote safety  Studies show that, when assigned to novel destinations, drivers using satnavs took, on average, 7 percent fewer miles per journey than drivers using paper maps  Fewer miles driven means, on average, less fuel consumed
Also, the drivers who used satnavs drove more carefully in that they were not taking their eyes off the road to check paper maps
Drivers who do not routinely need to drive to an unfamiliar location are more likely to plan out their route carefully prior to departure.