Real-time traffic information should take a big leap in accuracy in the spring when Clear Channel and partner Inrix start feeding traffic flow information from 625,000 transponder-equipped vehicles into their Total Traffic Network. This may begin to resolve concerns that traffic flow information now is too little, delivered too late.

In a test drive of the first car equipped with a Clear Channel / Inrix traffic package, the BMW's 3, 5, and 6 Series sedans, and the X5 SUV we found it not significantly different or better than a handful of other vehicles with real-time traffic. Other products and services with Total Traffic Network feeds include Nextel, Verizon SMS, Kenwood Electronics, Tom Tom Navigator GPS, MSN Autos, MapPoint, Cingular QPass, ATX, AAA, Rand McNally, Weatherbug, Microsoft SPOT, Siemens VDO, and Mio. Not all products from these makers have the real-time traffic reporting. But if they have the Total Traffic Network capabilities, they'll automatically be able to provide the upgraded service since to the portable navigation device (PND), it's the same data feed as before—just more accurate.

Real-time traffic, at least when it's working, provides speed information for major highways, pinpoints accidents, and in some cases offers alternative routes. Inrix hopes to provide a follow-on service, predictive traffic modeling, that will predict likely highway speeds on your route based on similar traffic conditions in the past. For that, new equipment will be needed.

Separately, Inrix says it now covers 92 markets and more than 50,000 miles of road with real-time traffic information. "Clear Channel's RDS customers will have available almost 10 times the coverage that they had available before this announcement," said Inrix' Mistele. "It's pretty exciting stuff."

The Clear Channel / Inrix service is free, although more accurately it can be said to be built into the price of the hardware; the other real-time traffic data service provided by the XM satellite service (the real-time traffic for your navigation system, not the major-market traffic channels on XM Radio) runs $5 a month. BMW, for instance, hiked the price of its navigation systems by $100 and for PNDs, real time traffic tends to be on the costlier models.