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LA combats congestion by synchronizing all 4,500 traffic signals

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los angeles traffic (Mikhail Tchkheidze / Shutterstock)
los angeles traffic (Mikhail Tchkheidze / Shutterstock)

Los Angeles is well known as a city plagued by gridlock, but a new traffic control strategy three decades in the making could help to ease the pain. That's the goal of the Automated Traffic Surveillance and Control system, which was completed in February and synchronizes all 4,500 traffic signals across the metropolis. Mayor Antonio Villaraigosa told the New York Times that LA is "the first big city in the world" to run all its signals in sync, and said that the system would cut down on both drive times and pollution. "By synchronizing our traffic signals, we spend less time waiting, less time polluting."

The system dates back to preparations for the 1984 Olympics, when certain intersections surrounding the Los Angeles Memorial Coliseum were synchronized. It works by sending updates in real time from magnetic sensors in the road through fiber-optic cables; a computer system using bespoke software automatically calculates signal timings based on the ebbs and flows of traffic. According to the Department of Transportation, traffic is 16 percent faster across the city, and the average driving speed has risen to 17.3 mph from 15 mph. That might not be enough to transform the experience on LA's streets, but we suspect residents and commuters will take what they can get.