Free-Market Gridlock
__ Wiring all 4 million roads in America would be prohibitively expensive. And even if the government could afford to build a Singapore-like network, the Feds couldn't get away with it. The freedom to drive anywhere, anytime, with minimal restrictions is considered an inalienable right by most Americans. As a result, the intelligent traffic systems evolving in this country tend to involve private sector companies and aim to serve drivers rather than control the roads.
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VIDEO CAMERAS, run by local and state authorities, record real-time traffic conditions. Video feeds are made available to other traffic info agencies - New York City's Transcom, for instance, has access to 400 cams around the city.
HELICOPTERS, though far less precise than electronic sensors at measuring congestion, are still the single most important source of traffic data.
CELL PHONES can be used as tracking devices by incorporating GPS and other location technologies. Companies such as US Wireless aggregate location data and generate dynamic maps of traffic flow.
E-ZPASS TOLLBOOTHS electronically charge commuters as cars zip through toll lanes. The windshield-mounted TRANSPONDER also contains a transmitter that sends speed data to Transcom readers located farther down the road.
BURIED INDUCTIVE LOOPS and OPTICAL SENSORS, used on only 5 percent of freeways nationwide, are operated by local and municipal transportation departments to collect speed and density information, which is stored in a public database.
TRAFFIC CONTROL CENTERS are operated by municipal DOTs as well as private companies such as Metro Networks, which runs 68 centers nationwide. Traffic data is gathered by electronic and human means, crunched, and then transmitted to radio and TV stations, Web sites, and wireless service providers.
ACOUSTIC SENSORS being developed by an SF Bay Area transit commission will be mounted on roadside posts to calculate traffic speed and density by analyzing the sound of passing cars.
HIGHWAY PATROL reports accidents and traffic snarls. The info is fed into public databases, some of which provide, via fax or email, an automated subscriber alert service for those needing immediate traffic information.
ROAMING TRAFFIC WATCHERS are employed by private information companies such as Traffic.com to provide on-the-ground, eyewitness reports.
