Last Flyover of Orange County Freeway Interchange Project Opens

A carpool bridge that links the San Diego and Costa Mesa freeways finally opened Friday, marking the end of a $125-million project to improve the Orange County interchange that has been plagued by construction defects and delays.

The 45-foot-high connector was supposed to open in April 2004, but material shortages, rain delays and design changes pushed back the opening nearly 13 months, said Sandra Friedman, a Caltrans spokeswoman.

Other parts of the project were riddled with problems, most notably a second carpool bridge in the interchange. Work was halted more than two years ago after workers discovered cracks in the concrete span, raising concerns that portions would have to be knocked down.

That connector opened in stages in December and January, 20 months behind schedule and nearly $3.5 million over budget. It is still unclear who will pay for the repairs.

Transportation officials breathed a sigh of relief at Friday’s opening of the flyover, which cost $61 million.

“I’m glad it’s open,” said Supervisor Bill Campbell, chairman of the board of directors for the Orange County Transportation Authority. “I’m hoping that this will improve the traffic flow in that whole area. Just the construction work with the cones and everything else slow things down.”

And Campbell wanted a more detailed explanation as to why it took so long: “I understand that concrete takes times to settle ... but I’ve driven by this and seen nothing happening week after week and that’s extremely frustrating.”

The project to improve the interchange -- one of the nation’s 10 busiest -- was funded through Measure M, the county sales tax for transportation projects. Drivers make about 506,000 trips a day through the interchange.

The flyover that opened Friday links the southbound San Diego Freeway to the northbound Costa Mesa Freeway and the southbound Costa Mesa Freeway to the northbound San Diego Freeway.

Unlike most carpool bridges which curve in one direction, the new bridge features a reversing curve. Traveling from the southbound Costa Mesa Freeway, the connector lane curves slightly to the right then slopes left before straightening out to link with the San Diego Freeway.

While the reversing curve is a device engineers use to minimize building roads over private property -- and therefore having to buy additional rights of way -- its use in flyovers is less frequent and can be startling to drivers.

“If we made a regular curve, like we did with the southbound lanes, we would have had to acquire property,” Friedman said.