Bing has announced they have added transit directions in 11 cities. Transit directions can be used to determine the best way to get from point A to point B via bus, subway, or local rail.
Bing released this feature for Boston, Chicago, Los Angeles, Minneapolis, New Jersey, New York City, Philadelphia, San Francisco, Seattle, Washington DC, and Vancouver and promises to keep adding more and more over time.
If you go to Bing Maps in one of those 11 cities, you should see a new directions icon. The directions icon shows a bus, which means all “transit” options. By clicking that option, you may get transit directions.
Here is a screen shot:
Google released their transit directions in 2005.