To trench or not to trench? That is the billion-dollar question.
That's according to a new engineering study that the city commissioned last year and that concluded that constructing a trench for Caltrain in the southern half of Palo Alto could cost up to $1.05 billion.
The project has been on the city's radar and wish list for years, with interest starting to resurge in 2009 as California's proposed high-speed rail project brought new focus on the city's rail corridor. In recent years, council members, planning commissioners and a specially appointed citizens committee that considered the city's official vision for the rail corridor all stated a preference for going underground with Caltrain and, ultimately, for high-speed rail. With undergound tunnels generally seen as cost prohibitive, the city has focused on open trenches as a more cost-effective option for improving safety and road circulation at the rail crossings.
Even that option, however, will be far from cheap, according to the Hatch Mott McDonald analysis. The firm evaluated two different trenching alternative, a 2 percent grade and a 1 percent grade, and estimated the cost to implement each one south of Oregon Expressway. The firm concluded that a 2 percent trench would cost about $488.2 million, while a 1 percent trench would cost more than twice as much: $1.05 billion. In each case, the rail traffic would be submerged under Meadow Drive and Charleston Road.
The firm concluded in its analysis that either design can be accomplished with no property acquisitions. By contrast, a design that sends roads under the tracks would cost $320 million but would require acquisition of 32 full parcels and seven partial parcels, the firm found.
The 2 percent grade is less expensive because it minimizes the length of the trench, which would begin just south of Matadero Creek and pass under Baron Creek, Meadow Drive, Charleston Road and Adobe Creek and return to grade just north of San Antonio Road. The alternative with a 1 percent grade would require an additional 10,000 feet of trench, as well as reconstruction of Oregon Expressway to remove the existing undercrossing and return the roadway to the same grade level as surrounding streets.
Even at $1 billion, the price tag for trenching Caltrain in the southern half of Palo Alto is expected to be far less than in the north half. That's because going all the way north would require a complete reconstruction of three grade-separated crossings Oregon Expressway, Embarcadero Road and University Avenue and submerging the city's two Calrain stations, according to report from the office of City Manager James Keene. The San Francisquito Creek, which passes along the border of Palo Alto and Menlo Park, would also pose significant design complications.
The staff reports notes that the study is "intended to facilitate community dialogue on the issue and ultimately to help form a policy position on grade separations."
"The study is not definitive in determining an ultimate configuration, but does provide a starting point for dialogue on the issue," the staff report states.
The City Council is scheduled to discuss the report and the trenching study on Oct. 20, at which point they will consider (but not vote on) whether to proceed with a future study that would include design work, refined project costs and assessments of feasibility. The study would cost $67,760.