SO finally webcams and sensors are being used for traffic information. See
http://www.nytimes.com/2005/07/19/business/19road.html?th&emc=th
What is happening to traffic is just the beginning of convergence of powerful sensor networks and internet technology. This convergence is beginning of the EventWeb. Current web is the web of documents — and since these documents need authoring, uploading, and then indexing the document web is not suitable for live information. By putting powerful sensors as a node on the web, a different kind of web is going to be created. This web will be at least as big a revlution as the document web created in early 1990s was. The technology required for this will be significantly different in many aspects — but as in earlier cases, it will be developed.