SALT LAKE CITY, Utah, Dec. 4, 2024, Gephardt Daily) — The Utah Department of Transportation has secured a federal grant for congestion relief, which it will use to install coordinated adaptive ramp meters (CARM) along southbound Interstate 15 from South Salt Lake to Bluffdale.
UDOT will be one of the first in the nation to use CARM, “a vehicle sensor system that adjusts ramp meters in real-time to improve traffic flow, cut travel times and enhance safety in congested areas,” says a news release issued by the agency. “It will also include five freeway to freeway ramp meters.”
UDOT Freeway Operations Manager Grant Farnsworth said I-15 “is a vital corridor, especially in Salt Lake County. Unfortunately, this valuable asset performs the worst when we need it the most. But CARM’s integrated sensor network will enhance travel times and reliability, making it easier — and safer — for Utahns to get to their jobs, families and other needs.”
Traditional ramp meters manage access to an interstate through traffic signals at on-ramps. Each ramp meter uses simple sensors in its area to inform wait times and determine when vehicles should enter the road.
CARM is more efficient, utilizing numerous vehicle detection sensors at all of its locations to assess conditions across the entire corridor and make real-time changes to ramp meter wait times, UDOT says, adding ramp wait times will be balanced throughout the system and monitored to not affect local streets.
“CARM’s superpower is its ability to ‘communicate’ with itself about current travel conditions,” Farnsworth said. “This connected system helps CARM make smarter and safer decisions as it guides travelers towards their desired destinations.”
With this real-time traffic intelligence, CARM can proactively address recurring periods of congestion, minimize bottlenecks and related traffic incidents and optimize the capacity of the interstate — all without having to add additional lanes, the UDOT news release says.
I-15 was identified as a high-need area for this project, as its capacity to transport vehicles during peak hours goes from 1,900 vehicles per hour per lane to 1,250 vehicles per hour per lane.
Construction is expected to begin in 2027 and CARM will be installed on southbound I-15 from SR-201 in South Salt Lake to the Point of the Mountain (14600 South and I-15 in Bluffdale).
