Google Maps has already been pretty good at providing public transit info.

The one problem is that it only went on typical schedules.

If there was a delay or a particular route was canceled, Maps wouldnt let you know.

Now, that changes with the addition of real-time transit info.

Google is rolling out real-time public transit schedules for certain areas.

Mind the (g)app for real-time transit information| Google Maps Blog viaAndroid Police