I-280/I-880/Stevens Creek Boulevard Interchange

Mark Thomas prepared a feasibility study, environmental document, and final design to improve operations, increase capacity, and enhance safety for the most congested interchange adjacent to one of the busiest shopping malls in the cities of San José and Santa Clara.

The project reconfigured the existing I-880/Stevens Creek Boulevard cloverleaf interchange (originally constructed in 1959) to a combination of par-clo and diamond configuration, which includes widening and realigning ramps, widening the overcrossing structure at Stevens Creek Boulevard over the freeway, and as well as improving the existing intersections at Stevens Creek Boulevard and Monroe Street. The project also included braided ramps to separate freeway-to-freeway traffic from the local interchange.

Project elements included 1,100 feet of freeway-to-freeway direct connector viaduct, a 2,400-foot Winchester Boulevard off ramp structure, pedestrian grade-separation, Stevens Creek Boulevard bridge widening, 14 major retaining walls, local street improvements, and sound walls. The redesigned interchange has reduced traffic congestion and delays by eliminating certain weaving and merging movements, while also improving access and enhancing safety for bicycle and pedestrian traffic.