Honda has recently (29-March) released a car traffic data system using Google Earth to present traffic status. According to newlaunches.com, the tool allows the company’s “InterNavi Premium Club” members to see traffic data overlayed on GE:
Traffic information is displayed in three colors indicating “smooth (blue),” “busy (orange)” and “congested (red).” Initial service area only extends to 20 km around the center of Tokyo, Nagoya and Osaka, but the coverage will expand nationwide.
The data is collected by Honda’s “InterNavi Floating Car System”, which apparently is installed on customer cars to track their data and share it with a central system. This probably gives very accurate real-time traffic data. But, I’m not sure whether that will be very popular in privacy-concerned countries. Apparently the system has already “collected data of total 100 million kilometers”. Here is the source of the story (in Japanese).