The reach of Google Maps just went locomotive, with the launch of Google Maps 5.7 for Android which introduces Transit Navigation in beta form.

Transit Navigation is the latest addition to the Navigation beta within the Android version of Maps, and brings public transport navigation for 400 cities around the world - including Traveline East Anglia, Traveline East Midlands, London overground, Traveline Scotland and Traveline South East here in Blighty.

Using your Android handset's GPS functionality the Transit Navigation beta tracks where you are on the, er, track, letting you know where you are and telling you when it's time to get off. You don't even have to have the app running full screen, you'll get notifications in the top bar warning you of your destination.

Obviously, it only works above ground - so don't rely on it on the tube.

Version 5.7 also brings improved driving and walking navigation options and a new UI for setting navigation routes.

There's also improved search suggestions with category icons and a new photo viewer for seeing place pages so you can take a look at what the place you are going to looks like before setting off.

Google Maps 5.7 is in the Android Market now. It's free and will work with any device packing Éclair or higher.