The $475 million improvement project is adding one regular lane and one carpool lane along the busy corridor traveled by more than 260,000 vehicles every day
ORANGE – As part of the ongoing improvements being made to SR-55 between I-5 and I-405, full nighttime freeway closures are planned for Friday, April 26, and Saturday, April 27, and drivers are encouraged to avoid the area or plan alternate routes during the shutdown.
All lanes of SR-55 between Edinger Avenue and Dyer Road – approximately a two-mile stretch at the border of Santa Ana and Tustin – are scheduled to close between approximately 10 p.m. and 5 a.m. both nights.
Westbound Warner Avenue over SR-55 is also scheduled to be closed during these times, as well as several ramps and connectors in the area. Detour signs will be posted, and drivers traveling through the area should plan for delays.
The closure is necessary to relocate utilities. Southern California Edison crews will be replacing power lines across the freeway and removing existing utility poles.
Find the latest closure and detour information here. More information is available on the project webpage at www.octa.net/sr55, where people can also sign up for the latest construction alerts.
The SR-55 Improvement Project, led by the Orange County Transportation Authority in partnership with Caltrans, is intended to help improve travel times in central Orange County along one of the most heavily congested freeways in Southern California. The $475 million project is funded through a combination of local, state, and federal funds, including $140 million from Senate Bill (SB) 1, the Road Repair and Accountability Act of 2017.
The project is adding one regular lane and one carpool lane in each direction of SR-55 between I-5 near Santa Ana and Tustin and I-405 near Irvine and Costa Mesa. It will also add merge lanes to help drivers more smoothly enter and exit the freeway.
SR-55 is a vital north-south freeway that links central Orange County and beyond to the coastal region. More than 260,000 vehicles use that stretch of SR-55 every day, and that number is expected to grow to nearly 275,000 vehicles by 2040.
The SR-55 Improvement Project is an essential part of fulfilling the promises made to voters through Measure M, Orange County’s voter-approved, half-cent sales tax for transportation improvements, also known as OC Go. It is expected to be finished in 2026.
