OCTA I-405 Improvement Project Website

The Orange County Transportation Authority (OCTA) in cooperation with The California Department of Transportation (Caltrans) is widening the San Diego Freeway (I-405) between State Route 73 and Interstate 605. This project will improve 16 miles of freeway, along with the replacement and widening of over 18 bridges. In addition, this project will add the 405 Express Lanes, incorporating the existing carpool lanes and a new lane in each direction.

Please click here for an interactive map.

Please click here for the closure list.

For up-to-date information and construction updates, please visit the 405 Improvement Project  Facebook page.

NB I-405 off-ramp to Seal Beach Boulevard to close for approximately one month

The NB I-405 off-ramp to Seal Beach Boulevard is scheduled to close for approximately one month. The ramp will be reconstructed as part of the freeway widening.

The ramp is scheduled to close at 5 a.m. Monday, June 29, and reopen July 29.

NB I-405 on-ramp from Seal Beach Boulevard closure

Crews are closing the northbound (NB) I-405 on-ramp from Seal Beach Boulevard during the day to continue pile driving activities for a wall adjacent to the ramp.

The daytime closure is set for 6 a.m. to 1 p.m. Thursday, June 18.

The detour is:
• NB Seal Beach Boulevard → NB Los Alamitos Boulevard → Westbound (WB) Katella Avenue →Southbound (SB) I-605 on-ramp → NB I-405

NB I-405 off-ramp to Seal Beach Boulevard

Contractors on behalf of the Orange County Transportation Authority (OCTA) will be conducting drainage work as part of the I-405 Improvement Project. Daytime closures are set for Tuesday, May 5th through Friday, May 8th between 6 a.m. and 4 p.m.