Google Maps Begins to Display Real-Time Public Transport Information
Google Maps already provides information on public transportation quite well. The only problem is that it only went on the standard schedule. If there is a delay or a particular route has been canceled, Maps will not inform you about this. Now everything changes with the addition of real-time transport information.
Google deploys real-time public transit timetables for specific areas. If you are in the UK, Netherlands, Budapest, Chicago, San Francisco or Seattle, you should notice that Google Maps will provide you with updated information throughout the day as it changes, rather than just showing you the expected timetable.
Check out Appendix (g) for real-time public transport information | Google Maps Blog via Android Police