|Huge opening day crowds at the Transbay Transit Center. Photo by Adrian Brandt.
Simple. Within a half mile radius of the Transit Center, there are more jobs than within a half mile radius of every station along the peninsula rail corridor from San Francisco 4th and King all the way to Gilroy, COMBINED! Even before high speed rail shows up, this is a piece of infrastructure that makes perfect sense. Or does it?
An epic opportunity for transit funding extortion
The clear (and, as of today's opening, agonizingly present) need for the DTX sets up a deliciously fat and juicy prey for the transportation-industrial complex, which you can think of as a hungry snake. Here we are, in a strong economy, in one of the richest cities on Earth, facing a specific and obvious transportation need: they can name just about any price. The latest estimate for the biggest meal that the snake can swallow is six billion dollars, and that's only the start. Scope creep, dizzying amounts of contingency cushioning, and construction change orders are sure to drive it far higher. Civil engineering megafirms, labor unions, and complacent and poorly coordinated government agencies are salivating at the prospect of feasting on the DTX. The bigger it gets, the more sated and comfortable everyone will be, with the notable exception of the suckers who pay taxes and ride trains.
The DTX project needs a major cost cutting exercise
- Delete the Pennsylvania Avenue tunnel extension. There is a perfectly serviceable tunnel already available. Engineering acumen should be brought to bear to overcome the (otherwise delightfully profitable) constraints of building a new trenched grade separation by figuring out how to shore up I-280 during excavation; how to cross the SFPUC's giant new sewer; how to duck under 16th street using a steeper 2.5% grade than the train people would prefer; and how to build temporary "shoo-fly" tracks under I-280 during construction now that the area is hemmed in by fresh UCSF construction. The usual paint-by-numbers engineering that deploys freight train design standards as "constraints" shows this to be categorically impossible, but is it really? Sharpen your pencils.
- Delete the mezzanine level at 4th and Townsend. Station mezzanines are a knee-jerk (and delightfully profitable) design feature of every recent piece of rail infrastructure in the United States. Wedged above the tracks, underneath, in the sky or in a cavern, mezzanines tend to sprout everywhere. In this case, a mezzanine makes passenger access more circuitous and pushes the track level much deeper, increasing the depth of excavation. The mezzanine and station become an enclosed underground space, triggering an avalanche of fire safety requirements that greatly increase cost and complexity, with all manner of vent structures and evacuation shafts. The right answer is simple, direct and free-flowing access from platform to street, and an open station ceiling that vents to the street through a slot built into a raised median on Townsend Street-- as wide as necessary to treat the structure as an open station under fire safety regulations.
- Daylight as much of the shallow Townsend Street portion of the alignment as possible, with a central median vent slot (just like in Los Angeles on the Alameda Corridor, where three of the nation's busiest diesel freight tracks are concealed beneath the street with a vent slot as narrow as six feet). This configuration has the potential to simplify the engineering considerations and costs related to fire safety, and even improves rail operations: without the onerous fire safety requirement of having only one train at a time occupy each tunnel ventilation section, operation of the entire DTX becomes less constrained.
- Slim down the three-track tunnel, another one of Sinclair's salary considerations, to two tracks instead of the planned three. The Rail Alignments and Benefits (RAB) operations analysis, carried out by a premier Swiss rail operations consultancy, concludes on page C-68 that "Under normal conditions, only two tracks are required in the tunnel
leading up to the TTC to operate the analyzed service plans. More
detailed analysis is recommended to identify the most effective
approach to provide infrastructure redundancy (e.g. the proposed third
tunnel track) to help mitigate the potential effects of major service
disruptions." The clear implication here, artfully worded so as not to upset Sinclair's salary men, is that a third track is not necessarily the best or only approach to achieve infrastructure redundancy.
- Add three 400-meter underground storage tracks, feeding in towards the Transit Center instead of the peninsula, along the northwest edge of the existing 4th and King station footprint. The fire safety requirements for this underground infrastructure would be less stringent because it would not be occupied by passengers. With beefy foundation columns bored down to bedrock to straddle this yard, the entire footprint of the site can still be redeveloped above grade, safeguarding San Francisco's desire to use "value capture" from this increasingly coveted parcel to finance DTX construction. The resulting train storage capacity is far more conveniently located than the remote yard sites currently proposed at Oakdale or Bayshore, reducing long-term operating costs. Even skyscrapers can be built on top of train storage: see Hudson Yards.
- Rationalize the Transit Center approach tracks to speed up train movements. The throat of the station has been identified as a key bottleneck for train movements (see RAB operations analysis page C-96, "Key Findings of Conceptual Planning"--and recall that you read it here first). An optimal layout has been identified that better enables concurrent arrivals and departures of two trains (see page C-117 of same). Precious seconds saved in the station approach can increase the traffic capacity of the DTX and make it more resilient to disruptions.
- Don't use exotic and expensive tunneling methods when their sole purpose is to keep businesses along the DTX route healthy during construction, by avoiding cheap but disruptive cut-and-cover methods. The intent is noble, and the recent impact of Central Subway construction in Chinatown is painful and fresh in our minds, but this sort of thing rarely pencils out for anyone but Sinclair's salary men.