Caltrans Begins Work on SR-76

📅   Fri January 08, 2010 - West Edition
Erik Pisor, CEG CORRESPONDENT


The estimated $240 million project will develop a four-lane conventional highway from South Mission Road to just east of Interstate 15. The SR-76/I-15 interchange also will be widened.
The estimated $240 million project will develop a four-lane conventional highway from South Mission Road to just east of Interstate 15. The SR-76/I-15 interchange also will be widened.

The first major San Diego County highway project to utilize American Recovery and Reinvestment Act funding has begun along State Route 76 in Oceanside, Calif.

The $181.6 million project, which will upgrade and improve a 5.5-mi. (8.8 km) stretch of highway, will receive $75.3 million in Recovery Act funding.

“We are taking a road (SR-76) that currently exists as a two-lane narrow, winding road and turning it into a four-lane expressway,” said Mark Phelan, project manager for Caltrans District 11, adding widening will occur from Melrose Drive to South Mission Road.

That portion of SR-76 has an average daily traffic volume of 30,000, with that figure expected to double by 2030. According to Caltrans, the accident rate along SR-76 consistently meets or exceeds the statewide average compared to similar two-lane roads.

“It is an urgent project,” Phelan said, adding San Marcos-based Flatiron Inc. officially began construction on Jan. 11.

Part of the highway widening involves the construction of a new 1,700-ft. (518 m) long bridge over the San Luis Rey River.

The two-lane, box-girder bridge will run parallel to the existing San Luis Rey River bridge, which after project completion will carry two lanes of one-way traffic.

During bridge construction, large rock drills will be used for the bridge’s piers. According to Phelan, the diameters of the rock drills are between 8 and 10 ft. (2.4 and 3 m).

The project has an anticipated completion date of December 2012, and will be constructed in four sequences.

Sequences 1 and 2 are currently underway and involve initial construction of the new bridge, and improvements/widening on SR-76 between the San Luis Rey River bridge and Olive Hill Road.

Throughout the next three months Flatiron will set up storm water and clean water measures, remove brush in the project area, and drill for bridge columns at the San Luis Rey River crossing, according to a Caltrans construction update.

Sequences 3 and 4 will begin in the summer of 2010 and involve improving SR-76 between Melrose Drive and the new San Luis Rey River bridge, and from Olive Hill Road and Sweetgrass Lane.

During all roadway improvement sequences new traffic signals and protective concrete barriers will be installed to eliminate head on accidents and allow for better traffic management.

When the project reaches completion, Phelan estimates that nearly one million cubic yards of dirt will have been moved. He also stated the project will not represent a large scrapper project due to the dirt and rock at the jobsite, and the project’s staging.

Unlike other Caltrans jobs, this project follows a design-sequencing model that allows Caltrans to build project elements, which have completed designs, while concurrently completing design of the remaining project elements and acquiring outstanding right of way.

“It’s almost design staging,” Phelan said. “If we went with the typical design-bid-build (process) we would probably be delayed nine months.”

The design sequencing method looks to accelerate a project that will have its share of challenges.

Because the project site is “butting up against” a highly-sensitive environmental setting, Caltrans and Flatiron will coordinate with environmental monitors; be sensitive to resources adjacent to the project area; and be prepared to encounter unidentified resources such as Native American burial grounds.

According to Phelan there are four endangered species whose habitat is in or near the project area.

Another project challenge includes water quality issues associated with the river, compliance with stormwater regulations, and the possibility of winter flooding, which could impede the project schedule.

Aside from Recovery Act funding, the project also will receive $16.8 million in Federal Demonstration Funds, $13.5 million in state funds, and $76 million from the TransNet sales tax administered by the San Diego Association of Governments.

The project represents the second significant improvement to SR-76, as a project that improved the highway from I-5 to Melrose Drive was completed in 1999.

When the current SR-76 project reaches completion in late 2012, Caltrans intends to start another improvement job along the roadway.

The estimated $240 million project will develop a four-lane conventional highway from South Mission Road to just east of Interstate 15. The SR-76/I-15 interchange also will be widened.

According to Phelan, the project is currently going through the environmental process and will hopefully be complete sometime in 2014.