Tracking cell phones for real-time traffic data

Although most new cell phones come equipped with Global Positioning System capabilities that can pinpoint their exact locations, the tracking technology used for transportation agencies does not depend on that.

Instead, it takes the frequent signals that wireless phones send to towers and follows the movement of the phones from one tower to another. Then it overlays that data with highway maps to determine where the phones are and how fast they are moving. Lumping thousands of those signals together can indicate traffic flow.

A Delcan demonstration Web site developed for Baltimore uses various shades of green, yellow and red to show block-by-block whether vehicles are moving at or below the speed limits. As rush hour started on a recent work day, observers could watch as green turned to yellow and then red on roads heading out of downtown.

The Baltimore project began this spring as a pilot program that monitors Cingular users over about 1,000 miles of road, but Maryland officials hope to eventually create a statewide version. (A Delcan competitor, Atlanta-based AirSage Inc., has an agreement with Sprint Nextel Corp. to monitor phones for its projects in Georgia and Virginia.)

Pete Rahn, director of the Missouri Department of Transportation, would like to make a similar Web site available to Missouri motorists, and to post estimated travel times on electronic road signs.

The Missouri and Maryland plans also assume that the contractor will market more detailed information to the private sector — automakers that offer onboard navigation systems, cell phone companies, shipping businesses or media that broadcast rush-hour traffic reports.

The private sector marketing helps drive down the states' cost. Missouri expects to spend less than $3 million a year on the service, Rahn said, although the exact price won't be known until the contract is finalized. Maryland is spending $1.9 million, although the entire Baltimore project costs nearly $5.6 million, said Mike Zezeski, director of real-time traffic operations for the Maryland Department of Transportation.

By contrast, the San Francisco Bay area spent about $35 million over several years to install roadside scanners and develop computer programs, Web sites and call centers for a real-time traffic service based on electronic toll passes, said Randy Rentschler, a spokesman for the region's Metropolitan Transportation Commission.

Officials considered using cell phone monitoring but opted against it, partly because of privacy concerns.

"We felt very strongly we had a bullet-proof privacy policy" with toll-pass monitoring, Rentschler said. "On cell phones, we could never do that."

As with cell-phone monitoring, the information received from the Bay area's toll scanners is anonymous. It's also encrypted and destroyed daily. But the local transportation commission went a step further, mailing 250,000 metal bags into which motorists could place their toll devices to prevent them from being monitored along the roads.

Cell phone users could accomplish the same thing by turning off their phones.

The Electronic Privacy Information Center (EPIC) suggests that someone should notify cell phone owners that their phones are being monitored for traffic data.

Privacy experts also worry that the traffic monitoring could later evolve into other uses — perhaps to catch speeders or fugitives.

That's because each cell phone has a unique serial number, in addition to its call number and a code that indicates its service provider. A cell phone company must always be able to track the location of its phones in order to know where to route a call.

"It's a mission creep issue that would be of most concern to consumers," said Lillie Coney, associate director of Washington, D.C.-based EPIC. "They may start out saying we want to know if there's a traffic problem and then take that information and start using it for different purposes."

MORE FROM WIRELESS

Wireless Section Front

BlackBerry users dealt with e-mail outages Teen runs up dad's cell bill to nearly $22,000 Google sharpens mobile focus with 'Nexus One' Nearly 1 in 3 older teens gets ‘sexting’ messages McDonald's to lift fee for Internet access Popularity of texting edging out cell phone calls Google may sell its own phone Teen drivers ignore anti-texting laws Study: Most U.S. wireless users satisfied AT&T: Tighter control of cell data usage ahead Wireless Section Front   Add Wireless headlines to your news reader: