You are running late so you take the corner a bit faster than you ought to – but a disembodied voice on the dashboard is having none of it.

A new generation of in-car navigation systems will take sat nav from being simply an electronic mapping device to being a driving instructor, telling motorists when to change gear, at what speed to take a corner and even how to drive more economically. NO this cannot be happening!

The Advanced Driver Assistance Systems (Adas), under development by leading sat nav manufacturers systems is due to be installed in cars within three years.

In addition to instructions on when to slow down or change gear for the best fuel economy, motorists will also be warned when they are driving erratically and will even be told at the end of the journey if they have caused undue stress to parts of the car.

Is today the 1st of April thus April’s fool’s day? Are we becoming such incompetent drivers we need a machine to tell us the error of our ways.

However, this is not a new idea for the Sat Nag has, in fact, been around for some time. Available from www.iwantoneofthose.com this handy device will come out with some cracking comments like "I know you're a man, but it's been 35 minutes now, so can you please admit you're lost and ask someone the way"; and "In 50 meters I'm going to put on my most annoying voice and say 'Is your short cut really faster when we get stuck in traffic like this, well, is it darling?" For just £7.99 this gadget is remarkably accurate!