Fountain Valley’s Slater Avenue bridge to close Friday for a year during 405 Freeway widening project

If you live or work in the Fountain Valley area, you might need to rethink your beaten path for the next year or so.

As part of a five-year widening project, the Slater Avenue bridge over the 405 Freeway is scheduled to close at 1 a.m. Friday, Sept. 21, for about 12 months.

Slater will be demolished in its entirety and rebuilt, said Eric Carpenter, spokesman for the Orange County Transportation Authority.

Other bridges that see heavier traffic will be reconstructed one side at a time so that they can remain in use – a lengthier process that will take around 18 months.

In the end, the 16-mile stretch between the 73 Freeway in Costa Mesa and the 605 in Long Beach will gain two lanes in each direction.

On Aug. 18, McFadden Avenue’s bridge, spanning Westminster and Huntington Beach, became the first of 18 to undergo reconstruction.

Slater’s demolition work will take place on two consecutive weekends, beginning Saturday nights Sept. 29 and Oct. 6. During demolition, both directions of the 405 will be closed overnight, from 11 p.m. to 8 a.m., between Brookhurst and Magnolia streets. Drivers will be routed off the freeway and detoured to the next open on-ramp.

After the widening, there will be five regular lanes and two express lanes – for a total of seven lanes. In place of the existing carpool lane, the express lanes will accommodate free-of-charge vehicles carrying at least three people.

The $1.9 billion project will be funded by four sources. Measure M, the county’s half-cent sales tax for transportation improvements, will cover $1.1 billion, the federal government $45.6 million and the state $89.7 million. A low-interest, 35-year loan of $629 million will be paid off by revenue from pay-to-use lanes.

For more information and to find suggested detours, go to octa.net/projects-and-programs.