Developing a 21st Century Public Transportation System?

Terje Mathisen asks: "Oslo has a pretty good public transportation system, consisting of local trains, subway, metro, trams, buses and ferries (to get across the fjord, and to some of the small islands). Now they want to put screens on all the central stops (about 300), showing the exact time until the next bus/tram will arrive. This will requires GPS units on the buses and trams, radio communication back to the central, some form of comms link back to each stop, and daylight readable screens. On all the remaining stops, they want to use SMS messages, so that you can use your cell phone to query the system. Do you know about similar setups anywhere else? How well do they work? How expensive was it to develop, and what costs were associated with the deployment and maintaintenance?"