Coverage of public transport options on Google Maps continues to incrementally improve. Cairns is the latest city to include a public transport option when offering directions, covering bus services in the greater Cairns area.
Cairns joins Perth, Adelaide, Canberra and Sydney's least useful transport service on the roster (along with Wellington in New Zealand). The service is due to be expanded to Townsville and Rockhampton in the near future. We've said it before and we'll say it again: Sydney! Melbourne! Brisbane!
Transit directions for Cairns in Google Maps [Official Google Australia Blog]