Google Public Transport Map to Reduce Carbon Emmissions?

Google has added Transit maps for public transport to its online maps. In Australia there is coverage of Adelaide (Adelaide Metro) and Perth (Transperth). There are also walking directions, as an alternative to directions for car drivers in the maps. This could be very useful for familiarising drivers, and those used to taking taxis, with public transport alternatives, reducing fuel use and carbon emissions. Where the Google transport maps are done in cooperation with the local transit authority, they are very detailed. Sydney's excellent Trip Planner, provides a similar service, but is not integrated with Google.