Verizon cell phones might aid traffic jam monitoring

Location data from 120 million Verizon cell phones, including some of those used by federal agencies, will provide information about traffic jams to Google Maps and other users of real-time traffic congestion data.

Verizon Wireless, a joint venture of Vodaphone and Networx contract holder Verizon Communications Inc., will provide anonymized data to Atlanta-based location services provider AirSage Inc.

Cell phones need only be turned on, not in use, for their signal to be available. But no personally identifiable data will be made available, said Verizon wireless spokesman Jeffrey Nelson. "Just location data from the GPS in your cell phone if you have opted to turn it on for location-based services," he said.

The agreement will quadruple the number of signaling messages AirSage will use in its Wireless Signal Extraction (WiSE) application to provide traffic information, predictive analytics and location services, Cy Smith, AirSage chief executive officer, said in a statement. When the data is fully integrated, he said, the company will have a database of more than 12 billion signaling messages across more than 200,000 centerline miles of roadway to power applications for government agencies, businesses and consumers.

Although AirSage currently focuses on real time traffic condition monitoring, it also is developing location services for commercial and emergency management use.

That also could include traffic monitoring by government transportation departments.

“Highways have traditionally been monitored using static sensors, which include loop detectors built in the pavement, radars and cameras along the road, and more recently toll card readers such FastTrak or EZ-pass,” said University of California, Berkeley, researchers Daniel Work and Alexandre Bayen in their report, "Impact of the Mobile Internet on Transportation Cyberphysical Systems: Traffic Monitoring Using Smartphones."

While such infrastructure, where it exists, "has proved to be efficient for highways," the report said, “the cost of deployment, communication and maintenance for such an infrastructure in the arterial network make it prohibitive or public agencies or companies to deploy on a global scale."

In the last five years, however, cellular phone technology has leapfrogged several attempts to build dedicated infrastructure systems to monitor traffic, the November 2008 report said. "Today GPS-equipped smart phones are progressively morphing into a ubiquitous traffic monitoring system, with the potential to provide traffic information in real time for the entire transportation network," the report said.

An evaluation in October by GeoStats Inc. of AirSage's traffic data quality in three cities, paid for by an unnamed third party, came to a similar conclusion. "AirSage’s performance was comparable to other similar traffic data providers," such as Traffic,com, said GeoStats spokesman William Bachman.

In Detroit, AirSage correctly detected congestion 88 percent of the time on highways and 84 percent of the time on arterials, GeoStats said. In San Diego, AirSage’s highway accuracy rate was 85 percent; arterial results were not summarized. In New York, the numbers were better: 93 percent accuracy on highways, 92 percent on arterials.

Determining accuracy is difficult, Bachman said, "because the same technology used over the same routes can yield different results each time it’s measured.”

Although dedicated sensor infrastructure results are currently more accurate — they count all vehicles — than cell phone-derived monitoring, the number of cell phones, which the Berkeley report puts at more than 3 billion worldwide, “will soon constitute one of the major traffic information sources available to the public.”

To ensure privacy and improve accuracy, the Berkeley researchers proposed a sort of hybrid data collection method in which Virtual Trip Lines, virtual geographic line segments deployed across roadways, trigger phones to collect and transmit data to the transportation system.

Verizon, of New York, ranks No. 16 on Washington Technology's 2009 Top 100 list of the largest federal government prime contractors.