Highway 99 will soon be impacted by pilot program. Here’s what Caltrans is testing

Traffic on Highway 99 may flow a bit differently in the near future.

Caltrans plans next month to install 10 “variable speed advisory” signs in the northbound direction, from Elk Grove Boulevard to the Highway 50 interchange in Sacramento.

“Beginning November 1 motorists will see VSA signs displaying advisory speeds that will change based on traffic conditions along the corridor,” Caltrans wrote in a news release Tuesday. “These signs will be operational during the weekday morning commute times as part of a pilot project.”

The pilot project is set to last at least six months. Caltrans says it is collecting the data to see if it “helps reduce stop-and-go traffic during high congestion travel times.”

The state transportation agency says its other goals are to reduce rear-end collisions and decrease vehicle emissions.

The speed limit on Highway 99 is 65 mph for most of the stretch between Elk Grove Boulevard and Highway 50. In a sample diagram, Caltrans showed the advisory signs displaying speeds as slow as 35 mph.

Advisory speeds are recommendations, meaning they are not enforced by California Highway Patrol and a driver “may not be cited solely for exceeding the posted value of an advisory speed sign,” according to the Caltrans speed limit manual. But advisory speeds could be a contributing factor in a driver being cited for violating the basic speed law, which says one should never drive faster than is safe for given road conditions, regardless of the posted speed limit.

Highway 99 is known as one of the most dangerous freeways in the U.S., with multiple studies in recent years labeling it the deadliest roadway in America.

In July, a Caltrans subcontractor was struck and killed in a hit-and-run on northbound Highway 99 near the Martin Luther King Jr. Boulevard exit, part of the stretch that will soon add advisory signs.