It's not often that we hear good news out of Los Angeles so brace yourself.

According to the NY Times, Los Angeles has synchronized every one of its 4,500 traffic signals across 469 square miles — the first major metropolis in the world to do so, and therefore, it's now possible, in theory, to drive from the Hollywood Hills to the San Pedro waterfront without stopping once.

But LA is obsessed with driving and with the number of cars on the road there continuing to rise (and almost seven million commuters already on the road each day during the rush in the metro area), even the system’s supporters say that it may not be enough to prevent gridlock from growing worse.

The Times reports that the traffic management system was built up over 30 years at a cost of $400 million and completed only several weeks ago. The Automated Traffic Surveillance and Control system, as it is officially known, offers Los Angeles one of the world’s most comprehensive systems for mitigating traffic.

The system uses magnetic sensors in the road that measure the flow of traffic, hundreds of cameras and a centralized computer system that makes constant adjustments to keep cars moving as smoothly as possible. The city’s Transportation Department says the average speed of traffic across the city is 16 percent faster under the system, with delays at major intersections down 12 percent.

Without synchronization, it takes an average of 20 minutes to drive five miles on Los Angeles streets; with synchronization, it has fallen to 17.2 minutes, the city says. And the average speed on the city’s streets is now 17.3 miles per hour, up from 15 m.p.h. without synchronized lights.

Other cities have chased to keep up, adopting centralized control of at least some traffic signals. But Los Angeles has remained at the forefront, with a system that is not only more widespread, but also faster and more autonomous than most others.

Now, the magnetic sensors in the road at every intersection send real-time updates about the traffic flow through fiber-optic cables to a bunker beneath downtown Los Angeles, where Edward Yu runs the network. The computer system, which runs software the city itself developed, analyzes the data and automatically makes second-by-second adjustments, adapting to changing conditions and using a trove of past data to predict where traffic could snarl, all without human involvement.

Long Beach and Gilroy, Calif., have already adopted the Los Angeles software, and Washington — the only city in the country that had worsae traffic congestion than Los Angeles last year, according to a Texas A&M report — has considered buying it as well, says Edward Yu, who runs the underground network.

“One intersection affects the entire network, so our system is very dynamic, constantly responding to demands of traffic,” Mr. Yu said. “But it takes a lot of infrastructure to do what we do. Other cities have similar operations. Ours is just very comprehensive,” Yu noted.