Visit this page often for news and updates on the OCTA I-405 and 55 Improvement projects.

Currently, the San Diego Freeway (I-405) is one of the most congested freeways in Orange County, carrying more than 300,000 vehicle trips in some sections each day. By 2040, traffic volumes on the I-405 are expected to increase significantly. The I-405 Improvement Project will increase freeway capacity, improve traffic and interchange operations, and enhance road safety to meet state and federal standards.

OCTA in cooperation with The California Department of Transportation (Caltrans) is widening the San Diego Freeway (I-405) between State Route 73 (SR-73) and Interstate 605 (I-605). The widening includes the addition of one general purpose lane in each direction on I-405 from Euclid Street to the I-605 interchange, plus tolled express lanes in each direction of I-405 from SR-73 to SR-22 east. The tolled 405 Express Lanes and the existing HOV lanes would be managed jointly as a single tolled express facility with two lanes in each direction from SR-73 to I-605.

The Costa Mesa Freeway (SR-55) is one of the most heavily congested freeways in Southern California. SR-55 is a vital link to other major freeway systems in Orange County, and it is the only freeway providing a direct north-south connection between Central Orange County and the coastal region. Currently, SR-55 between Interstate 405 (I-405) and Interstate 5 (I-5) has four general purpose lanes, one carpool lane and some auxiliary lanes in each direction. The heavy congestion on SR-55 is expected to increase with future demand. This project will add new lanes to this stretch of the freeway to help with traffic flow and improve traffic operations.

For information about these projects and to sign up for email alerts, please visit OCTA's web page.