An algorithm determines how fast you should drive on this Calif. freeway

Instead of spending millions of dollars to widen a congested freeway, the Riverside County Transportation Commission has opted to spend a fraction of that on a pilot project to make traffic on the road flow more smoothly.

On June 1, the commission launched its "smart freeway" on 8 miles of the northbound lanes of Interstate 15 in Temecula. On-ramp meters at Temecula Parkway, Rancho California Road and Winchester Road are now managed by an algorithm that helps control the flow of cars onto the roadway and offers a suggested speed.

Unlike typical on-ramp stoplights that run on a timer lasting a few seconds, Interstate 15 drivers could find themselves waiting up to four minutes or even longer while the system determines the necessary speed for traffic entering the freeway. By spacing out the cars, transportation officials hope to improve traffic flow, reduce stop-and-go traffic and decrease the amount of time that travelers have to spend on the freeway.

The transportation commission spent $33 million to build the project, which will run for two years. Riverside County Transportation Commission spokesperson David Knudsen told SFGATE that if the program is successful, the agency will work with Caltrans to deploy it elsewhere in the county and then potentially to other traffic choke points in California.

"This system is a lot less expensive than trying to build new lanes, and so the idea here is let's make the system that we have work better, " he said.

Knudsen said the program is not managed by artificial intelligence but instead uses advanced sensors in the roadway to monitor real-time traffic conditions and make adjustments. The stretch of freeway that connects Temecula at the Riverside/San Diego County line to the Interstate 215 interchange in Murrieta can be notoriously clogged. What can be less than a 10-minute drive with no traffic can take between 25 and 45 minutes during the afternoon peak period, according to the transportation commission.

"The intent is to create a consistent flow of traffic on the freeway system, and the coordinated ramp metering among the three on-ramps ... will help do that," Knudsen said. "If we can manage that, then we can help prevent that stop-and-go traffic frustration that so many people feel ... on the freeway."

Designed and implemented in Australia, the program is still rare in the United States. From fall 2021 through the following summer, Colorado pioneered a similar design on Interstate 25 in Denver, which has since been expanded to other freeways throughout the state.

In both places, the technology improved traffic flow. Australian drivers saw between a 35% and 65% reduction in travel times, and in Denver, travel times fell by around 20%.

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This story was originally published June 9, 2026 at 7:05 PM.