Google has launched a new feature on its mapping software in America that will allow drivers to see traffic jams as they happen overlaid on its maps.

The free service, which is available for 30 major US cities including San Francisco, New York, Chicago and Dallas allows you to see up-to-date traffic conditions to help you plan your schedule and route.

"There's nothing worse than getting stuck in traffic when you have some place to go", quipped a Google employee on its blog.

Coloured coded overlays will show the amount of congestion drivers can expect to encounter. Red, you're looking at a stop-and-go commute; yellow, you could be a little late for dinner; green, you've got smooth sailing.

No word as yet when or if it is coming to the UK.