There’s a new watchdog carefully monitoring major Salt Lake Valley intersections.
It’s called lidar, which stands for light detection and ranging. The technology uses eye-safe laser beams to measure the distance and movement of cars, pedestrians and cyclists alike in order to understand how to make intersections safer and more efficient for all.
Right now, lidar is only fully operational at two local intersections: 5900 South and State Street in Murray; and 2100 South and Redwood Road in Salt Lake City, near Glendale Golf Course, according to the Utah Department of Transportation.
But there are plans to expand. The next intersections expected to see the technology fully operational include 700 East and 1300 South in Salt Lake City, near Liberty Park; and 300 West and 600 North, in the Marmalade neighborhood.
What exactly does lidar do?
The technology works similar to echolocation, which is how bats are able to sound out their surroundings.
The laser beams target and perceive what’s going on in an intersection in order to recreate it in 3D. That way, the 3D view can be studied for things like how and where near-miss crashes are happening, whether green light times are too short, and whether crosswalk times should increase.
There are currently three other ways that Utah monitors traffic signaling, but they don’t compare to lidar, according to Mark Taylor, a traffic signal operations engineer with UDOT. Those three methods include inductive loop, video and radar.
The inductive loop method is highly accurate but struggles to pick up bicycles and pedestrians, Taylor said. It involves installing a wire system in the pavement of intersections to detect vehicles.
Video monitoring looks for pixel changes in imagery to detect vehicles. But this method falls short when weather conditions such as shadows and heavy rain can cloud cameras.
Using radar to detect vehicles is the most common method in Utah, Taylor said. But lidar is more precise, detecting cars 99.8% of the time.
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This article is published through the Utah News Collaborative, a partnership of news organizations in Utah that aims to inform readers across the state.