Dim traffic sensors dull how ‘smart’ freeways are

California’s highways aren’t as smart as they used to be.
Buried under thousands of miles of pavement are 27,000 traffic sensors that are supposed to help troubleshoot both daily commutes and long-term maintenance needs on some of the nation’s most heavily used and congested roadways. And about 9,000 of them do not work.
The sensors are a key part of the “intelligent transportation” system designed, for example, to detect the congestion that quickly builds before crews can get out and clear an accident.
A speedy response matters: Every minute a lane is blocked during rush hour means about four extra minutes of traffic. Fewer sensors can mean slower response times, so the fact that 34 percent are offline — up from 26 percent in 2009 — creates an extra headache in California’s already-sickly traffic situation.