OCTA to close 405 Freeway in Costa Mesa from 11 p.m. Friday Sept. 28 to 5 a.m. Saturday

OCTA Crews will close the northbound lanes of I-405 between Fairview Road and Harbor Boulevard at 11 p.m. Friday to remove a sign structure as part of the I-405 Improvement Project.

The sign structure, which must come down to allow crews to start constructing the new outside lanes as part of the freeway widening, spans the northbound lanes. The northbound lanes of the freeway must be closed to safely remove the sign. Two lanes on southbound I-405 also will be closed for the activity.

Motorists on northbound I-405 will be detoured to the Fairview Road off-ramp, then directly back onto northbound I-405 at the Fairview on-ramp. Motorists on northbound State Route 73 also will exit at the Fairview off-ramp and be directed to northbound I-405 at the Fairview on-ramp.

Up-to-date closure and construction information is available on the project’s interactive map at www.octa.net/405map.

Reminder: Full I-405 Closure Begins Saturday Night in Fountain Valley

Drivers and nearby residents are also reminded that, the next night, a full closure of the I-405 in Fountain Valley is scheduled. That closure, which will close all lanes of I-405 between Brookhurst and Magnolia streets, is set to begin Saturday, Sept. 29, lasting from approximately 11 p.m. to 8 a.m. Sunday, to safely demolish the Slater Avenue bridge.

The remaining work on the Slater bridge will be done during a second full closure on Saturday, Oct. 6, also from approximately 11 p.m. to 8 a.m.

The Slater bridge is the second of more than 18 bridges to be built, widened or replaced as part of the project, which will speed up travel times on I-405 between Costa Mesa and the Los Angeles County line, an area traveled by more than 370,000 vehicles a day. The McFadden Avenue bridge was demolished last month.

During the freeway closures, northbound drivers will be detoured off the freeway at Brookhurst Street, and southbound motorists will be detoured off the freeway at Magnolia Street.

Nighttime lane closures on I-405 are also expected during the weeks of Oct. 15 and Oct. 22 for additional demolition activities, but those will not require the freeway to be fully closed.

Drivers should expect nighttime delays in the area and are encouraged to use alternate routes if possible.

The $1.9 billion I-405 Improvement Project will add one regular lane in each direction between SR-73 and I-605 and a second lane in each direction in the center of the freeway that will combine with the existing carpool lanes to form the 405 Express Lanes.

This 16-mile segment of I-405 is one of the most heavily traveled stretches of highway in the nation, and both the regular lanes and carpool lanes are heavily congested during rush hour and on weekends. The project is critical to accommodate expected employment, population and housing growth throughout the region.

People are encouraged to visit the project website at www.octa.net/405improvement to sign up for construction alerts via automated call, text message or email.