The San Francisco Bay Area automated toll system, Fastrak, may be used to collect traffic flow data. Basically, they’re adding sensors along the highways which can pick up passing Fastrak boxes. They promise to keep the data separate from driver info, but since the existing Fastrak system is designed to track the passage of specific cars through toll plazas, you gotta figure the capability will be there. I figure the first time there’s a high-profile man hunt, the new sensors get used to track cars, for perfectly understandable reasons. Who’d want to tell the public “No, we’re not using every possible method to track that kidnapper and his victim.”? Not me. Better not to have the capability.