The West Approach is a one-mile stretch of Interstate 80 in the heart of a thriving residential and commercial area in San Francisco. The California Department of Transportation deemed the structure, originally constructed in the 1930s and partially rebuilt in the 1950s, as lacking adequate seismic resilience. However, a straightforward retrofit of the existing structure was too costly, time-consuming and detrimental to traffic. Caltrans chose a retrofit-by-replacement, in which traffic would be diverted onto temporary roadways so the original structure could be demolished and rebuilt.
This was considered one of the most complex projects in Caltrans history. The West Approach needed to be rebuilt in its original footprint, but had to be done in a way that did not adversely affect the almost 300,000 vehicles that cross the structure daily. Challenges that the team faced in this extraordinary effort included the following mandates:
- No loss of mainline and ramp capacity during peak commuter hours.
- Staying within the original footprint of the structure (no additional right-of-way acquisition)
- Minimizing nighttime disruptions to nearby residents
Through the partnering effort the West Approach team effectively worked together to eliminate potentially significant delays to the project, and with these efforts were able to complete the project seven months ahead of schedule. At the beginning of the project, the team encountered a number of unforeseen circumstances that were estimated to possibly delay the project 19 months. Through innovative and aggressive re-sequencing of traffic and demolition staging, the team was able to eliminate the delay.
The project’s budget was set at $429M with a target completion date of August 2009. The project completed at budget, seven months ahead of schedule in January 2009 and began in 2003.
California Department of Transportation
Winner: 2008 Caltrans Partnering in Motion Award