Nightly freeway lane and ramp closures begin for I-405 improvement project


Drivers are encouraged to check for updated closure information on

Intermittent nighttime lane and ramp closures on I-405 started recently and will continue routinely as construction for the I-405 Improvement Project ramps up.

Closure information is available and updated in real-time on a mobile-friendly, interactive map available at

Nightly closures will start as early as 9 p.m. and are expected to be finished by 5 a.m. weekdays and 7 a.m. weekends. It is recommended that drivers plan ahead to avoid delays by checking the interactive map and singing up for weekly construction alerts on the project website. All necessary freeway lane closures for the project are expected to occur overnight.

The $1.9 billion highway project, the largest under construction in California, is being led by the Orange County Transportation Authority, in partnership with Caltrans. The project adds one regular lane in each direction, between Euclid St. and I-605, as promised to voters through Measure M, Orange County’s half-cent sales tax for transportation improvements. The project also adds a second lane in each direction, which combined with the existing carpool lanes, will create the 405 Express Lanes.

Weather permitting, construction activities will continue over the next few months, including restriping portions of the freeway and setting up concrete barrier on the outside of the freeway to protect work areas for activities such as tree removals and grading.

More significant construction activities, such as the first paving operations and bridge demolition activities, are anticipated to begin later this year. The project is set to be completed in 2023.

For more information on the I-405 Improvement Project or to sign up for construction alerts, visit



Please enter your comment!
Please enter your name here