The Autoweek reports that the navigation system with real-time traffic data -- first introduced in the Acura RL as a standard feature - has an obstacle. The system displays icons where crashes and other incidents occur. It has color-coding for roadways, to show how freely traffic is flowing. In theory, if you see a problem on your route, you pick an alternative. But there is a glitch that isn't the system's fault: Real-time traffic information is limited and spotty.

Real-time information is available in 31 U.S. metropolitan areas, about a third of the U.S. metro areas with at least 500,000 people. The data generally come only from major highways in those areas. Even in Los Angeles, which has one of the best systems, just about 60 percent of roadways are covered. So what can be done to fill the gaps?

Full story: Autoweek