Beating Traffic By Joining the Network
New System Takes and Shares Data From Cars

By Peter Whoriskey
Washington Post Staff Writer
Tuesday, March 25, 2008


For a solitary driver, the ebb and flow of traffic can be maddeningly unpredictable.

So some tech entrepreneurs wondered what would happen if all of those isolated drivers could be connected and warn one another what lies ahead.

The idea will get a closely watched tryout this week, when Dash Navigation begins selling two-way GPS devices for cars, creating, in essence, a network of drivers. A central computer will collect speed and location information from each car, then create and transmit back what the start-up company hopes will be the most complete and up-to-the-minute picture of traffic ever created.

Based on the once-futuristic notion of the "hive mind" -- essentially, the aggregation of what everyone in a group senses individually -- the effort reflects what many consider one of the most fertile areas for innovation: collecting and analyzing data from disparate but newly linked sources.

A driver who installs a $599 Dash unit would, in theory, be able to learn about the traffic ahead from someone in the network who had just experienced it. It's like Web efforts that rely on a group of users -- Wikipedia or Amazon's book recommendations, for example. But the Dash network will operate in real time and rely less on humans for input than on the devices. The more people who have the devices in a given area, the more accurate the information.

"We thought that if we could have all these cars connected, we could really change the experience," said Rob Currie, Dash's president and chief operating officer.

The units have been tested near Dash's home base in Sunnyvale, Calif., and in other cities around the country, including Washington, where travel delays from congestion are the second-worst in the United States, according to the Texas Transportation Institute. Starting Thursday, the company plans to begin selling the devices, which offer traffic information, directions and Internet search.

"Dash is right on the front end of the next wave of devices and applications that harvest ambient data and then build real-time services from it," said Tim O'Reilly, a publisher of computer books and organizer of the influential MySQL tech conference.

Dash's effort is considered the first mass-market attempt to use GPS-based tracking with such a potentially broad U.S. audience. GPS devices in cars have until now provided directions but not such potentially broad-based real-time traffic information.

Entrepreneurs, truck fleets and cellphone companies have been experimenting with similar ideas for years and have encountered thorny issues of privacy and accuracy along the way.

As criminals, cheats and others have discovered to their dismay in recent decades, a person who uses cellphone or GPS technology can be a lot easier to track. Use of the technology to monitor traffic has repeatedly raised questions about whether the tracking data might be used for other purposes.

A 2005 experiment by the Maryland Department of Transportation, for example, was scuttled after complaints that the cellphone data gathered from unwitting passersby to gauge traffic speeds could be used to track those cellphone users. That system measured speed by collecting information on how fast cellphone customers were moving between cell towers.

Other states, including Missouri and Georgia, have pursued or are pursuing similar plans. Georgia has deployed two services that use the cell-tower data to gauge traffic speeds on major roads in the state.

"We're not spying on anybody," said Paul Marshall, a spokesman for the Georgia Department of Transportation. "When we tell people about it, we say, 'We have a new way of getting traffic volume and speed information.' . . . They get paranoid when they hear it's cell data."

The cellphone data that the state receives, however, are "anonymized" -- that is, stripped of any identifying information such as the user's phone number -- and that allays most people's concerns, officials said.

The location information Dash gathers -- which by contrast comes from GPS coordinates, not cell-tower data -- will similarly be anonymized, company officials said.

"If the FBI comes in tomorrow and says, 'Where were you at 3 p.m. yesterday?' the honest answer will be, 'We don't know,' " Robert Acker, Dash's senior vice president of marketing, said.

The Dash device also offers a layer of what might be called domestic privacy: It allows users to delete recently searched-for destinations and services. Internally, company officials call that "the girlfriend program."

The thorniest technological challenge facing efforts like Dash's is how to turn the mountain of minute-by-minute location data from cars into a sensible map of traffic.

Simply translating a car's speed into traffic levels doesn't work. A car's slow movement might only reflect a slowpoke behind the wheel. A faster speed might only reflect an aggressive driver, or someone cruising the HOV lane. And unless they are properly accounted for, stoplights could look like traffic jams, which is why earlier efforts focused on highways alone. To address such problems, the Dash software looks for patterns in the data and throws out the outliers.

"It isn't enough to take the data and say this is the speed on the roadways," said Bryan Mistele, president of INRIX, a traffic-reporting company spun off by Microsoft that provides the baseline data in Dash's system. "You have to figure out what's going on."

The INRIX system started with more traditional methods of traffic detection -- embedded road sensors, radar -- but now largely relies on information received from commercial truck and taxi fleets, which account for more than 700,000 vehicles.

On a short test drive last week around Sunnyvale, the Dash unit displayed listings of nearby restaurants and gas stations. Out on the roads, it offered a combination of reasonably reliable traffic information based on average levels for that time of day and data from a scattering of other people testing the units.

Generally, roads that were free-flowing were marked green, and congested areas were marked red or orange. But one congested off-ramp that should have been marked in red on the screen instead showed green. No Dash user had recently been over that stretch, and so it showed the average traffic level there for that time of day.

Timothy Dilks, 29, a systems engineer who lives in Alexandria and works in Reston, was among the 20 people selected to test the units around Washington. Dilks, who got involved with the test by answering an ad on a technology Web site, described himself as obsessive "when it comes to navigation and knowing where I am" and said he has owned five GPS devices over the past decade.

He called the Dash "pretty amazing," a marked advancement because it offers both better traffic predictions and access to information from the Web.

"It definitely helps to know how long it's going to take to get there," he said. "Unfortunately, there's really no alternate routes on my commute, so if I'm stuck on I-495, I'm stuck."

The company hopes that by using INRIX's traffic data as a baseline, and by offering Internet access, it will draw customers before the Dash driver network becomes widespread.

Whether the Dash venture works out, experts in the field say that eventually one of the companies experimenting with the technology will get it right.

John Frawley, executive vice president of broadcast operations at Westwood One, which provides traffic information to more than 2,400 radio stations around the country, including WTOP, called it the industry's hottest topic.

Once it works, "this kind of GPS tracking is going to make some of the older technology obsolete almost instantaneously," he said.

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