SR 152/SR 156 Improvement Project

The 152/156 Improvement project reconfigured the hazardous, heavily traveled intersection of State Routes 152 and 156, dramatically enhancing safety and relieving traffic congestion. Previously, drivers on westbound 152 had to turn left across fast-moving oncoming traffic to reach westbound 156, and the accident rate at this intersection was twice the statewide average for this type of highway facility.  Biggs Cardosa designed a one-lane grade-separated flyover structure that carries eastbound 152 and allows westbound 156 motorists to pass safely beneath.  Biggs Cardosa’s innovative design, which included tall abutments with locked shear keys, enabled the structure to be built with a reduced bridge length, achieving considerable cost savings while still maintaining seismic safety.  Another innovative solution for the project involved creating a left exit for motorists transitioning between westbound 152 and westbound 156, rather than a right exit, as is more typical on highways.  This saved costs by eliminating the need for a second grade separation.  Completed on budget and six weeks ahead of schedule, the flyover has greatly reduced traffic congestion and improved safety at an interchange that has long been known as one of the area’s most dangerous highway intersections. This project received the ACEC California 2009 Merit Award for Engineering Excellence, the APWA Silicon Valley Chapter 2009 Project of the Year Award and the 2010 Project of the Year in the Infrastructure category by the Northern California Chapter of the Construction Management Association of America.

LOCATION
Santa Clara County, CA

Old Mountain View-Alviso Road Bridge Replacement (HBP)

Biggs Cardosa was the prime consultant providing project management and structural engineering for the replacement of a structurally deficient bridge due to severe deck cracking and spalling, delaminated concrete, speckled rust and flaking on steel members and inadequate bicycle and pedestrian access and being within the 100-year floodplain.  The new bridge is 52 feet wide and has two 12-foot-wide traffic lanes, as well as shoulders, bike lanes and sidewalks. Its pavement is new, as is its floodwalls, curb, gutter and street lights. The bridge also has been “elevated to meet the Santa Clara Valley Water District’s requirements for design flood clearance in Calabazas Creek.  The project is shared with the city of Santa Clara and the city of Sunnyvale and is a great example of the coordination between agencies to successfully complete a critical project.

LOCATION
Sunnyvale, CA

Interstate 580 WB HOV Lane Widening

Biggs Cardosa is providing structural engineering services for the widening of approximately 13 miles of westbound Interstate 580 to provide a westbound High Occupancy Vehicle (HOV) lane beginning west of Greenville Road Undercrossing and ending west of the San Ramon/Foothill Road Overcrossing in eastern Alameda County. The project is divided into two construction contracts. As part of the project, several bridge structures will be widened. Widened structures include both street crossings and crossings over creeks. Also included in the project are numerous retaining walls.

LOCATION
Alameda County, CA

Davis Street and Marina Boulevard OC Replacement (I-880 SB HOV Lane)

As part of the Alameda County Congestion Transportation Commission I-880 SB HOV Lane Project, Biggs Cardosa was contracted to provide structural design services for the replacement of bridges at Davis Street and Marina Boulevard. The replacement structures eliminated the safety concerns associated with substandard vertical clearances and the existence of multiple supports with substandard shoulders. In addition to these traffic safety goals, the replacement structures accommodate a new SB HOV lane to increase capacity in the I-880 corridor, reduce the accident rate, and reduce traffic delays for both HOV and mixed flow vehicles.

LOCATION
San Leandro, CA