I have been stalked before. I figure I don't have any privacy. I don't like it. The agencies and companies behind these high-tech systems say they use a range of safeguards, including letting travelers choose whether to participate. All the motorists are volunteers.
Some systems try to limit the amount of personally identifiable information they collect.
For instance, Transcom, a traffic management organization, has set up automated roadside readers in the New York area to track cars with E-ZPass tags. But tag numbers are scrambled so they cannot be traced to their owners. He said the equipment does not determine specifically which vehicle is tuned into which station. But in low-traffic areas, it could be easier to identify individual cars. A third safeguard used by some systems is the practice of collecting data about large groups of vehicles rather than specific cars.