An Algorithm Determines How Fast You Should Drive On California’s I-15 Freeway

Riverside County has launched an 8-mile “smart freeway” pilot on northbound I-15 near Temecula, using roadway sensors and an algorithm to coordinate ramp meters and suggest speeds rather than widening the freeway. Officials say the $33 million project could reduce stop-and-go traffic and travel times. According to SFGATE, similar systems in Australia and Denver reportedly cutting delays by 20% to 65%. From the report: 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.”