Traffic lights are stupid things. We’ve all encountered thoroughfares that create stop-and-go traffic by throwing up one red light after another. We’ve all sat at a late-night intersection, waiting for a red light to change, irritation mounting as we observe that no cars whatsoever are using the cross street. Surely, we’ve all thought, there has to be a better way.
It turns out that the National Transportation Operations Coalition agrees. A new study, the “National Traffic Signal Report Card” concludes that improper signal timing accounts for 5 to 10 percent of all traffic delays, and could be significantly improved for an investment of less than $1 billion annually. (Examiner.com has a brief story here, which I’ve based this blog post on. I could not access the Report Card itself, available here, this morning, probably due to heavy traffic.) Reports Examiner.com:
Some of the biggest problems cited are those that each of us experience on a regular basis, including: (1) signal sequences where drivers pass through a green light at one intersection only to find a red light at the next intersection. (2) making drivers stop at intersections where there are no vehicles and no pedestrians at the cross street. (3) intersections where drivers must sit through more than one green cycle of lights. …
The coalition says that management of traffic signals on a national level rates at “D-,” the operation of individual signals gets a “C” but the coordination among traffic signal systems gets a “D.” The worst grade of all goes to traffic monitoring and data collection, which gets an “F.”
The key to creating “smart” traffic lights is setting up sensors and monitors that can track traffic speeds and the number of cars backed up behind a light, and then adusting the length of traffic signals dynamically — either through human operators at a central station or through artificial intelligence. It’s certainly not a cure-all. But, then, neither is building building more roads. The problem, of course, is that the traffic light lobby isn’t as powerful as the construction lobby, so only pennies are spent where dollars are needed.
