Before leaving to meet his friend for dinner the other night, Sakae Fujimoto checked the local traffic report. Instead of flipping stations on the radio, he booted up his in-car navigation system. "Where would you like to go?" a computerized female voice inquired. Fujimoto specified an address in Shinagawa, a Tokyo district 16 miles north of his apartment. When a map appeared on his monitor, red arrows showed that a traffic jam was blocking one of the main roads into the city. The voice came back to warn him that there had been a car accident 500 yards ahead; Tokyo-bound traffic was slowing to a crawl. But there was good news, too: the screen displayed five quick alternate routes into town, with estimates of how long each would take. He chose one, and 30 minutes later was sitting down over Korean barbecue with his friend.
Traffic has been the bane of city living for more than 2,000 years. When the streets of ancient Rome grew jammed with carts, vendors and oxen, the caesars banned daytime deliveries altogether--only to have residents complain of being kept awake at night. In the early 1900s, streetcars were buried underground to make way for automobiles and, more recently, cities binged on road building to speed travel from downtown areas to the suburbs and back. Now road congestion has reached a new crisis point. A 2001 report from the World Business Council for Sustainable Development in Geneva estimated that urban residents in developed countries spend double and triple the amount of time in traffic that they did 20 years ago. The average annual delay for American drivers climbed from 11 hours in 1982 to 36 hours in 1999, according to the Texas Transportation Institute.
City planners are attacking this age-old problem with a 21st-century tool: wireless communication. "Building streets is expensive and we don't have the space for it in our modern cities anymore," says Bernd Leitsch, an engineer who is helping to roll out a system in Berlin similar to Tokyo's. "We have to use what we have and make traffic flow better. That can only be done through technology."
Cities from Berlin to Los Angeles are pinning their hopes on so-called advanced traveler-information systems, much like the one Fujimoto uses. They rely on thousands of sensors embedded in the asphalt, attached to street signs and hidden in traffic lights that record data on traffic flows and density and deliver it, wirelessly, to computer servers. Computers then combine this information with police dispatches on accidents or emergencies and deliver it to users who can access it on PDAs, mobile phones and the Internet. In Japan, 10 percent of drivers rely on such systems, and that number is growing rapidly.
Berlin's system is likely to be the most advanced of all. Developed over the past 10 years at a cost of $16 million by the city government and corporate giants DaimlerChrysler and Siemens, the Traffic Management Center--or VMZ in its German initials--will not only give a snapshot of road delays but also predict what traffic conditions will be like in several hours. It gathers live data from 125 infrared sensors posted at major streets and 40 Webcams at key intersections. It combines these data with past patterns, including speed, flow, construction sites, road closings, temperature and precipitation, and feeds them into a battery of computers. The machines then tell city drivers the quickest way to get from point A to point B. "It's like a weather forecast, only more exact," says Leitsch, the VMZ's director.
Los Angeles, which has some of the most congested roads in North America, has a similar pilot program in place. Called PEMS (Performance Evaluation and Monitoring System), it receives information from loop detectors, electrical wires buried beneath the pavement that send traffic data every 30 seconds to a computer server at the University of California, Berkeley. City officials hope the system will eventually be able to tell travelers exactly when they should leave home in order to reach their destinations on time.
These information systems alone are unlikely to make a large dent in traffic patterns worldwide. They don't encourage drivers to leave their cars behind, for instance, unlike London's widely praised congestion tax, where drivers are fined for entering the city center during peak hours. But city planners hope that a combination of such innovative approaches will restore to drivers something that traffic jams take away: the freedom to roam.