A Work in Progress

I-5/I-805 Project Opens

By David Silva

Workers recently completed the northbound portion of San Diego's Interstate 5/Interstate 805 widening project, a $175 million effort the California Department of Transportation hopes will alleviate chronic congestion on the interchange - at least for a time.

The project will add a bypass from the I-5 and I-805 merge to the Del Mar Heights Road Interchange. The goal - for now -- is for the bypass to be used primarily by trucks using the first two lanes north of the junction, thus relieving the pressure the slower-moving vehicles create at the bottleneck. Truck drivers will not be required to use the bypass. The project also includes the addition of a high-occupancy-vehicle lane on the southbound I-5 at Carmel Mountain Road, and auxiliary lanes on both freeways.

Construction started in March 2002. The new northbound lanes opened to traffic in February, although the southbound portion won't be completed until at least fall 2007. Caltrans architects designed the expansion, and Yeager Skanska of Riverside is the general contractor.

"Overall, we're getting very positive feedback from the public on the project," said Mohammed Khan, senior resident engineer for Caltrans. "More than 270,000 vehicles a day pass through this junction in every direction. Interstate 5 is the lifeline for northern San Diego. The public demand to relieve congestion here was huge."

Just how much the widening project will relieve congestion, Khan said, is uncertain. Given such variables as traffic growth, the impact on the system by other freeway improvements and the fact that the studies on which the project was based are more than 15 years old, accurate predictions how the project will affect traffic is almost impossible.

"It makes sense to reevaluate the project when it's finished to see if a truck bypass is the best use of the improvements," Khan said. "That decision will be made sometime in spring 2007."

The fickle nature of Southern California traffic essentially made the design of the widening project a work in progress. As time passed from the 2002 start date of construction and Caltrans laid plans for separate freeway projects -- most notably a proposed widening of the I-5 from San Diego all the way to Oceanside -- Yeager Skanska found itself confronted with numerous change orders, said Kurt Thomas, project superintendent for the firm.

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"We basically redesigned the whole job to accommodate the future widening improvements," he said, laughing when asked whether the project presented significant challenges. "Caltrans hit us with a change order for an 84-inch steel casing with an entrance pit 25 feet deep that we had to jack under the freeway. This had to be done on one side of the freeway in order to build a retaining wall eight-tenths of a mile long and seventy feet high on the other side.

"We had built this job across Los Peñasquitos Creek, and that had some environmental challenges such as water pollution and stormwater control."

The project is the first major Caltrans undertaking to fall under a new regulation requiring environmental remediation of any polluted runoff into a natural body of water. Yeager Skanska built four bridges across Los Penasquitos Creek and dropped nine concrete piles - the largest 12 ft. in diameter - into the creek. According to Khan, the mesh surfacing of the piles should filter pollution from the water.