Institute of Transportation Studies at UC Berkeley

The Bay Area is experiencing a period of rapid economic and population growth that is testing the transbay transportation system and exacerbating equity concerns around housing and health. Along with growing challenges in system operations, these conditions make it particularly important to consider the case for a new transbay crossing that could potentially help improve urban and regional accessibility, unlock new land uses, and create a more resilient transportation network for a stronger, healthier, more equitable region. This report analyzes the potential of a new transbay crossing to provide additional travel capacity between San Francisco and the East Bay, complementing the existing Bay Area Rapid Transit (BART) tube and the San Francisco-Oakland Bay Bridge. This project would be larger in scope than the combined scale of many other major Bay Area transportation projects of recent years and has the potential to be significant for the ninecounty region, the Northern California megaregion and the State of California. This new crossing is commonly referred to as the “second crossing.” However, we call it a third crossing because it would augment both the existing Bay Bridge and BART tube transbay connections if constructed.