From Jason at the Florida GIS Data Blogspot:

• XM NavTraffic Data Service Expands to 44 Major U.S. Markets

With almost 7 million subscribers, XM Satellite Radio announced the arrival of XM NavTraffic, the first nationwide satellite traffic information service for GPS navigation systems.

Here are some of the features:

• "XM NavTraffic delivers real-time traffic information to vehicle navigation systems. The driver can see current traffic conditions on the nav screen, such as traffic speeds, accident locations, and road closings. "
• "Accidents and road construction are identified on the map by icons, alerting users to potential blockages up ahead and allowing the driver to route around a jam before getting caught in traffic. In markets where the data is available, XM NavTraffic also provides an overlay of color-coded traffic flow information, indicating how fast the traffic is currently moving on the driver's chosen route. Traffic data is aggregated by NAVTEQ Traffic digital map information from multiple data sources, including police and emergency services, commercial traffic data providers, road sensors, traffic cameras, eyewitness reports, and real-time aircraft surveillance reports. "

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