Green sat-nav - how it works

Yesterday silicon.com reported on developments by Swedish academics to build a greener sat-nav system that works out the most fuel-efficient routes.

It might be a long way off hitting shop shelves or being bundled with vehicles but here's how the tech-savvy traveller of the future might use this green gadget:

silicon.com Retail & Leisure

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Step One
Jump into your car, destination in mind, then programme it with your start and end points.

Step Two
The green sat-nav works out the most fuel-efficient route, as opposed to the fastest or shortest route.

Step Three
The sat-nav works from a collection of special routes it has stored. Every route, made of various roads, has a pre-assigned value for fuel efficiency. For example, a straight, wide, downhill road where you can drive continuously at 60mph gets a better fuel-efficiency rating than a windy, uphill road with twists, pot-holes and a speed limit of 30mph.

Step Four
The sat-nav considers the time of day, works out whether the roads are likely to be congested and checks real-time information on traffic.

Step Five
The device uses car and fuel type to work out what sort of roads the specific vehicle is suited to. A smart car - for example - could happily drive along narrower roads without stopping compared to a large 4x4.

Step Six
With all this information processed the green gadget comes up with the most fuel efficient route for a journey.

Step Seven
On arrival, there is even a calculation on the proportion of fuel that has been saved versus traditional fastest or shortest routes.