SAN JOSE, CA - MAY 19: The Berryessa/North San Jose BART station is photographed through a sculpture titled "LIFE!" by Lawrence Kirkland during VTA’s BART Silicon Valley Berryessa Extension signing ceremony signifying that all safety related tests have been completed, verified and accepted, in San Jose, Calif., on Tuesday, May 19, 2020. (Anda Chu/Bay Area News Group)
A panel of subway experts has endorsed the Valley Transportation Authority’s “single-bore” design for the BART extension to San Jose, concluding a months-long independent review of the contentious plan to dig a massive tunnel through downtown.
Anthony Burchell, one of the experts, said a switch from the VTA’s existing design to a more conventional twin-bore would be “disastrous” and mire the project in red tape and delays.
“Don’t change,” Burchell, who is heading a major metro project in India, told VTA board members at a meeting Thursday night. “I still think two years minimum is the delay you’ll get if you change now.”
Burchell’s statement came just over six months after the VTA’s board called on agency staff to commission a panel of independent experts who could give a clear-eyed view on the agency’s BART project in an attempt to satisfy critics who say the single-bore design is leading to ballooning cost estimates and will hamper passenger access. This week the VTA said the funding needs of the project have risen by 35% to $9.3 billion with a start a 2034 date with a multi-billion dollar budget shortfall.
The independent peer review, which was led by the American Public Transportation Association, was meant to help guide VTA leaders as the BART extension through downtown San Jose approaches key milestones and faces a multi-billion dollar budget shortfall. In December, the board is slated to vote on a $460 million package to order a massive tunnel-boring machine that could seal the fate of the project’s tunnel-boring method.
But a pair of VTA board members raised questions Thursday night about the experts’ review.
“I have serious concerns about how the scope of work was defined for this project,” said VTA board member Sudhanshu Jain. He questioned the review team’s estimate of a two-year delay since the review did not factor in previous advanced-stage designs for the twin-bore project.
The review panel seemed to lack “some very fundamental things,” said Palo Alto Mayor Pat Burt. “I’m pretty concerned on those aspects.”
The experts said their conclusions were based on international and domestic cost trends along with the experts’ decades of experience in the field. But they faced pushback from two board members after acknowledging that the study did little examination of extensive documents underlying the agency’s 2018 decision to nix a more standard tunneling method known as twin-bore in favor of a more innovative, but potentially risky, tunnel design known as single bore.
“We investigated this basically not knowing what design had been done on the other twin bore already,” said David Carol, APTA’s chief operating officer.
Both the single-bore and twin-bore methods were analyzed under the state’s environmental impact law known as CEQA. The twin-bore design plans were 65% complete when the VTA and BART boards voted to make the switch in 2018 and the single-bore designs were about 35% complete as of March 2022.
One transit expert, Donald Richards, told the board Thursday evening that his understanding of the study was to look “mainly at the technical aspects.”
“We did not look in detail at the cost and environmental implications,” said Richards.
The six-mile, four-station BART extension, managed by the VTA, is slated to be the largest infrastructure project in Santa Clara County history. The project was approved by nearly 71% of Santa Clara County voters in 2000.
In the VTA board-approved memo from May, which authorized the review San Jose Mayor Sam Liccardo, board chair Chappie Jones, and San Jose councilmember Raul Peralez called for “an additional independent analysis to be conducted on the single- and dual-bore options, building on the independent analyses provided by outside firms and large metro transit agencies in 2017.”
The analysis, they wrote, should provide a “clear view of the trade-offs” between the two tunneling methods, including passenger safety, rider experience, cost, and construction delays.
The single-bore tunnel design, which was pioneered in Barcelona, is meant to spare downtown San Jose years of construction chaos. The project envisions a massive single tunnel deep underground carrying to tracks of BART trains. This method would not require tearing apart large parts of Santa Clara Street.
The more standard twin-bore design would mine shallower side-by-side tunnels that require digging up sections of the street. In August, the VTA presented a revamped tunnel design of 48 feet in diameter – about the width of a four-lane freeway – which transit advocates say would relieve many of the passenger access and safety issues posed by the single bore.
In a statement, Liccardo said he would have “preferred” an independent review underpinned by “all of the details about the extent of environmental analysis previously performed.” But he said the high-level review “confirmed what earlier independent analyses revealed: a traditional dual-bore design will not yield any safety, cost, or constructability benefits, but the delay of switching designs now will add years and hundreds of millions in cost.”
Burchell said for international projects twin-bore tunnels are “typically cheaper and quicker” but in the United States the knock-on effects of tearing up the street, including environmental and legal challenges, would cut into potential cost savings.
Originally published at Eliyahu Kamisher