TomTom and Navteq develop "Sat Nag"

Two of the biggest players in the sat nav arena have teamed up to produce a device that promises not only to get you to your destination, but makes sure you drive safely on the way.

The Advanced Driver Assistance Systems (ADAS) is a joint venture between TomTom and Navteq.

As well as the usual directional features, it will also warn drivers if they are hogging a lane, taking corners too fast, if you're in danger of having a crash, and will even tell you when to change gear to maximise fuel economy.

The sat nav manufacturers add that it will also show the road in 3D giving details such as the steepness, road width and whether there are any obstacles - something they hope will be a real advantage for lorry drivers.

Aside from the safety features - the ADAS will also offer detailed directions to hard to get to tourist sites as well as recommending restaurants along the route.

The first of the devices are expected to be on shelves in the next three years, although the Daily Telegraph suggests that car manufacturers such as BMW and Audi are expected to install the new devices in all their new models from now on.