Dave from Google posted in two Google Maps Help threads that the public transit layer is not working on Google Maps.
There are several reports that it hasn't been properly working in any of the cities for the past few days.
Dave from Google replies yesterday saying:
Yes we're still working on a fix. We generally avoid giving ETAs on a fix like this because software can be a complex business, and things sometimes take longer than expected. The main thing we want to avoid is breaking something else while fixing this issue! Apologies for the inconvenience.
So, I am not sure when it will be resolved but Google is aware of the issue and they apologize.
