There are 4,114 Intersections in LA, and He Controls Them All

Jon Bruner profiles Los Angeles Department of Transportation Engineer Edward Yu, and the ATSAC system run by Yu and his team, which controls the timing of traffic lights at each of the city's 4,114 intersections.

To judge by the level of congestion that the average driver confronts every day on the streets of Los Angeles, some might argue that Yu and ATSAC aren't doing a good enough job. But the Automated Traffic Surveillance & Control system (ATSAC), is adaptive, and as it builds a rich database of historical traffic statistics and patterns it is learning, so give it some time.

ATSAC was first implemented in 1984, the first such system in the country, and it proved itself quickly, despite what rush hour horror stories might tell you. "Repeated studies since the 1990s have found that travel times fall by 15% near connected signals and motorists make 20% to 30% fewer stops, massive improvements for a cost of about $150,000 per intersection. "

Full Story: 4,114 Stoplights in Los Angeles and the Intricate Network that Keeps Traffic Moving


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