The BART extension project to downtown San Jose is finally set to begin construction in summer 2024, but concerns over safety are mounting due to the Santa Clara Valley Transportation Authority’s (VTA) insistence on using a single-bore tunnel design. This $12.7 billion project has led to ongoing tensions between BART and VTA, particularly regarding emergency evacuation protocols.
Documents recently obtained by NBC Bay Area reveal that BART clearly expressed reservations back in 2017 about the feasibility of evacuating all passengers from the station to safety within six minutes using the single-bore design. Despite these concerns, VTA has remained steadfast, asserting that there are adequate safety measures in place to ensure passenger safety.
The VTA’s rationale for pursuing a single-bore excavation is primarily cost-related, claiming it minimizes disruption to surface traffic in downtown San Jose. However, the extension’s deepest point reaches 100 feet—a depth that is double that of BART’s 18 existing deep stations. Similar evacuation issues were highlighted earlier this year when a fire at the 12th Street station in Oakland forced a full evacuation.
In a 2017 notice, BART emphasized the challenges associated with the five-mile extension, which has a diameter of 54 feet and is designed as a single bore. According to a former BART fire safety engineer, Barney Smits, the difficulty of emergency evacuations was rated as “very high” based on a professional assessment, pointing out that there are “serious hindrances at six or seven points” throughout the tunnel.
During a recent interview, Smits reiterated that the VTA seems unwilling to make any changes. He highlighted that passengers will need to rely on three sets of escalators to reach the platform, but these escalators will automatically cut power during emergencies, leaving passengers on the lowest level to climb eight flights of stairs to reach safety.
“The scenario assumes there are 2,000 passengers on the platform and that firefighters are rushing down; completing an evacuation within the six-minute safety window is simply impossible,” he explained, referencing guidelines from the National Fire Protection Association.
BART board member and civil engineer Liz Ames expressed concerns about whether VTA’s persistent stance has cast a shadow on safety. She, along with fellow board member Debora Allen, has called for BART to provide assurances regarding safety, as the issues surrounding the single-bore tunnel remain unresolved, a sentiment echoed by Smits.
The difference between a single-bore and double-bore tunnel is critical: in the event of an incident, passengers in a double-bore tunnel would have an additional tunnel for evacuation, while a single-bore design could trap individuals if one end is blocked by a fire.
VTA, however, maintains that there are alternative refuge spaces within the station, located on both sides of the platform, allowing passengers to avoid smoke and fire if they cannot reach the surface. They assert that this design meets all regulatory standards and is currently under review by federal and state authorities, as well as local safety agencies.
Nonetheless, questions remain not only about station safety but also about the evacuation process in the event of a fire within the tunnel, as well as issues related to heat and smoke removal. VTA claims that the extension will feature a “single-point exhaust system,” which will automatically activate to remove heat and smoke from the tunnel, purportedly offering greater efficiency than methods used by BART.
