over the past six months, San Francisco's Transbay Terminal Center (TTC) project has been the topic of numerous posts on both this blog and the Caltrain-HSR compatibility blog (index at the end of this post). So why am I revisiting this wretched topic yet again?
Well, as Henry Kissinger once famously paraphrased Sayre's Law: "The reason academic politics are so bitter is that so little is at stake." Right now, there's a $400 million grant application from the Transbay Joint Powers Authority (TJPA) to the Federal Railroad Authority (FRA) at stake and, CHSRA is about to ask for $1.28 billion of its own just for the SF-San Jose segment. In addition, the state of California plus several Bay Area counties plus the city of SF are positioned to commit substantial funds of their own on behalf of taxpayers. This dispute is no longer academic, so somehow TJPA and CHSRA need to come up with a face-saving compromise. However, that's no reason to lock in every poor single poor decision each authority has made in this context to date.
My objective is to summarize the problems and, to suggest a variation that may be palatable to all sides (see map at end of post). I doubt this post will actually make a blind bit of difference either way in FRA's decisions on the respective grant applications. However, having stirred the pot vigorously, including off-line contacts with TJPA by way of a member of its Citizens' Advisory Council (CAC), I'd like to at least make sure I didn't leave this last stone unturned. So please, indulge me.
Note: just in case this isn't clear, all of the alternatives mentioned below are based on underground station facilities and approaches to them. (h/t commenter spence)
San Francisco's Transbay Terminal Center was conceived as a joint effort by the city of SF, Alameda county's AC Transit and Caltrain to achieve two objectives:
- to extend the financial district into an area of urban blight south of Mission and,
- to relieve rush-hour congestion at the downtown BART stations (Montgomery and especially, Embarcadero)
To its credit, the city of SF set out to redevelop the entire area with transit access in mind to avoid increasing congestion on both the bridge and city streets. Land near the terminal that is currently used for at-grade parking lots is to be converted to multi-story buildings, a combination of office towers and affordable apartments.
San Francisco voters approved this concept 7:3 via SF city prop H(1999):
SECTION 2. As part of the extension of Caltrain downtown, a new or rebuilt terminal shall be constructed on the present site of the Transbay Transit Terminal serving Caltrain, regional and intercity bus lines, MUNI, and high speed rail, and having a convenient connection to BART and MUNI Metro. Said terminal shall be so designed and constructed as to:The legal basis for the TTC project therefore requires construction of both a downtown train station for Caltrain and a transbay bus terminal for the benefit of city residents and commuters. The DTX tunnel and train station are neither optional nor were they an afterthought. Note the requirement for the "most convenient" and ADA-compliant pedestrian connectivity between Caltrain and BART/SF Muni subway in the downtown area.
(a) yield the highest possible transit use by residents and commuters;
(b) afford senior citizens, persons with disabilities, and other commuters with the most convenient connections between regional bus lines, MUNI, Caltrain, and BART;
(c) produce the highest density of foot traffic, in conjunction with foot traffic from the Caltrain station, to accommodate mixed use retail development;
(e) result in the lowest feasible combined costs for construction of the bus terminal and the Caltrain station, without sacrificing the aesthetic qualities of the terminal and station and their interface with surrounding development.
SECTION 3. [...] electrification of the Caltrain line from San Francisco to San Jose prior to or concurrent with the extension of Caltrain downtown [...] tunnel boring techniques [...]
Prop H also mandates Caltrain electrification prior to start of operations and a tunnel that is bored rather than excavated from above via cut-and-cover. The tunnel and railway station infrastructure were subsequently mapped to a second phase of the project because at San Jose's insistence, Santa Clara county refused to commit its share of the electrification funding in light of the sky-high cost of extending BART to Santa Clara. Section 3 explicitly rules out partial electrification, so SF could not proceed until CHSRA offered to come to the rescue. Shoot foot, reload.
TJPA interpreted point 2(c) to mean that the downtown train station would have to be physically underneath the bus terminal to maximize foot traffic and hence, lease revenue from a co-located shopping mall that is supposed to help pay for the project. Amazingly, it also believes this configuration will result in the lowest total construction cost (cp. point 2(e)), even though every tunnel curve excavated under existing buildings is extremely expensive. Shoot other foot.
The option of constructing tracks under nearby Beale Street to create a station that would be intermodal with both the bus terminal and with Embarcadero BART at Market Street was rejected for the following reasons: tunneling risk near the Bay Bridge anchorage, limited width that would require a multi-story station and, potential problems with box sewers under Embarcadero and Mission plus the foundations of older buildings between Market and Mission. There is also a desire to reserve Mission Street for a second BART line served by a second transbay tube, a very expensive project that may one day become indispensable.
An underground station under Main Street (best viewed in satellite mode, zoom in for details of track layout) and land just west of it would permit up to 11 staggered tracks in a single level, seven of them full length (1320'). Afaik, this was never studied, perhaps because it wouldn't generate enough foot traffic for the aforementioned retail outlets. It's all about the shopping, getting from A to B be damned.
The upshot of all this is that the design now features a "train box" with just six platform tracks parallel to Mission Street. The western end of all six lies roughly at the western end of the existing terminal building. In an effort to minimize tunneling cost, TJPA selected an approach via Townsend and 2nd rather than 3rd - let alone one via 7th and Minna or a station under Mission Street. The result is a sequence of three extremely tight curves in the final approach into the train box.
Note that the northern four tracks have since been extended to Main Street at CHSRA's request. The very expensive excavated tail tracks were moved to the southernmost tracks, which are nominally reserved for Caltrain. Harmonizing platform height to the level required for HSR would eliminate hard platform track assignments and hence, the need for tail tracks.
While trains can get around tight curves, this is not at all recommended if their axles are rigid. TJPA cites the example of the main station in Cologne (Germany) whose throat features a minimum curve radius of 550 feet. Please turn up the volume and watch the video below to get a sense of what wheel squeal on the top of the rail sounds like in the real world. Nails on a blackboard have nothing on this. In the TTC, the sound will be even more painful to passenger's ears as the acoustically hard surfaces of a tunnel and underground station tend to concentrate sound volume. The associated wear and tear on both wheels and rails also tends to increase rail/wheel noise emissions all down the line and/or maintenance overheads.
The curve at Townsend and 2nd is similarly tight and, TJPA's engineers and consultants have talked it into needlessly using only straight switches and constructing not two but three tunnel tracks all the way to 4th & Townsend. This forced the use of slow, labor-intensive sequential excavation over a conventional two-track tunnel boring machine.
Separately, Clem Tillier has pointed out problems with the configuration of support columns, including those on the platform tracks which may impede pedestrian flow to and from the island platforms. He has also lamented the lack of architectural grandeur below the surface, imposed by the inclusion of a full concourse level. He cites the interior of Berlin's Central Station as an example of what billions of dollars can buy you.
Note that TJPA claims the orientation of the train box retains the option of one day running trains to the East Bay via a transbay link for standard gauge services. This is not rquired by prop H(1999) and a bit of a crock, at least for HSR, if only because tunneling under the tall buildings between Main and Embarcadero would be prohibitively expensive. More to the point, there is zero room for dedicated HSR tracks between Oakland and Benicia. For the moment at least, there's insufficient demand for single-seat standard-speed service between SF and Sacramento to justify the construction of a fixed link for standard gauge tracks. For the price of just that, you could finance a ton of improvements to Amtrak CC, including bypass tracks and tilt trains for express service between Emeryville and Sacramento.
Summary of legitimate complaints against TJPA:
- failure to anticipate that the catchment area of the SF HSR station spans multiple counties, meaning that high ridership depends critically on excellent connections to all existing high-capacity rail transit systems
- failure to commit to an ADA-compliant pedestrian passage to BART/SF Muni
- loud wheel squeal (and associated wear and tear) due to three tight curves
- extremely long station throat (= low throughput)
- extremely expensive three-track tunnel to compensate (= stupendous cost)
- poor aesthetics of and possibly poor pedestrian flow to and from platform level
- doubtful claim of option for future standard-gauge fixed link to East Bay
One reason there is now such tension between TJPA and CHSRA is that that latter agency was hamstrung by a four-year delay in getting prop 1A(2008) onto the ballot, compounded by a year spent on a starvation budget imposed by Gov. Schwarzenegger who was dissatisfied with the lack of private investors in the funding plan. Since he who pays the piper calls the tune, this massively weakened CHSRA's leverage in negotiations with TJPA while it was making decisions on the underground portions of the project.
In particular, CHSRA failed to insist on an underground pedestrian tunnel all the way to a BART/SF Muni subway/streetcar station, even though HSR ridership will depend heavily on excellent connection to these existing high-capacity rail services and prop H(1999) actually requires something along these lines. Forcing many thousands of passengers to hoof it across busy city streets every day is not an acceptable outcome for a multi-billion dollar project.
For order-of-magnitude reference, BART delivers about 60,000 transbay passenger trips on a normal
One reason CHSRA may have been reluctant to kick up a fuss years ago is this telling assertion in the Bay Area to Central Valley Final Program EIS/EIR (chapter 8, pp20 PDF):
The capital costs needed for the HST component of the Transbay Transit Center (including the 1.3-mile extension) is estimated to be similar to the estimated costs for the 4th and King option. Since the rail component would be shared with Caltrain services, the Transbay Joint Powers Authority funding plan assigns only a portion of the rail related Transbay Transit costs to the HST system.As if an HSR station at 4th & King wouldn't be shared with Caltrain! Given that facility is at grade and has 12 platform tracks, CHSRA evidently believed at the time that the HSR project's share of the cost of the anyhow-planned DTX tunnel and train box would be quite small, but it failed to get that in writing from TJPA. Now, the forecast for the underground portion is on the order of $2.8 billion and TJPA wants the HSR project to fund the lion's share of that on top of Caltrain electrification. Section 2704.04(2) of AB3034 turned CHSRA's preference for the TTC into a hard mandate. Shoot foot, reload.
CHSRA is also locked into the idea that San Francisco is the end point of a train trip from Southern California. It insists on dwell times of 30-40 minutes in the TTC, even though AB3034 mandates feasible headways of no more than 5 minutes for the entire HSR network. With just four platform tracks at the TTC, dwell times above 20 minutes - including the time needed to traverse the throat twice - are out of compliance. Unfortunately, instead of trying to bring down dwell times, CHSRA is now looking for ways to secure more platform tracks in SF. AB3034 limits the network to 24 stations and 4th & King is too far from downtown for anyone to argue with a straight face that it could somehow be considered part of a modified TTC design. A relatively cheap tunnel + station with four straight full-length platform tracks, intermodal with Civic Center BART/SF Muni, with an option for four more under 8th (h/t to commenter Andrew), is now also out of the question for HSR.
Worse, since TJPA already has a Record of Decision on its design, any major changes at all would jeopardize its grant application against the $8 billion HSR portion of ARRA and invite the wrath of an entire city. Shoot other foot.
Ergo, CHSRA should get cracking on reducing dwell times to below 20 minutes so it can make do with four full-length platforms. One way to achieve that is to redefine the route of any given train as SoCal to SF and back again. This would preclude cleaning and light housekeeping of the seating areas in SF, but then Amtrak doesn't do that nor reprovision the cafe cars every 400 miles, either. The restrooms could be cleaned one-by-one en route in the SJ-SF-SJ segment. Cleaning staff could use Caltrain to commute if required. A little lateral thinking by CHSRA would go a very long way here.
Summary of legitimate complaints against CHSRA (in this narrow context):
- incorrect/naive assessment of cost exposure to TTC project during HSR program-level EIS/EIR process
- failure to analyze any alternatives to create a single Central Railway station served by HSR, Caltrain, BART, SF Muni subway and SF Muni streetcars
- inefficient operations concept, leading to excessive dwell times and need for more platforms than TJPA could reasonably make available while still meeting its commitment to Caltrain under prop H(1999)
- failure to focus technical complaints on genuine design flaws
- failure to raise the alarm early enough
For better or worse, the political reality is that CHSRA's chances of getting TJPA to abandon its train box under the bus terminal are now slim to none. In part, that's a result of Gov. Schwarzenegger's actions but there's plenty of blame to go around.
A reasonable approach might look as follows:
- Accept that at least some HSR trains are going to have to use the TTC train box, warts and all. In the early years of operations, make that 100% of HSR trains. Change operations concept to reduce dwell times in SF to below 20 minutes and ensure compliance with the 5 minute headway requirement in AB3034.
- Get the city of SF to commit to a second, separate EIS/EIR for constructing a dedicated underground pedestrian passage between Embarcadero BART/SF Muni and the HSR tracks under
MainBeale Street (this was already studied in 2007 but remains unfunded). Design it complete with bright lighting, moving walkways and security staff, to actually implement the spirit of section 2(b) of prop H(1999). In addition to connecting to the concourse level, consider also connecting to the BART island platform from below to address existing pedestrian flow constraints there. Those will only get worse as the financial district expands south of Mission. Start of operations would have to be concurrent with that of the TTC train box.
- Consider using Talgo equipment, since that is the only manufacturer to offer both double-deck commuter and suitable high-speed trains with very short cars, individual axles for each wheel and passive steering of each wheelset. That means they can negotiate very tight corners with reduced squealing (the tractor cars still have conventional rigid axles). If other trains vendors are chosen, prioritize the development of dry lubricant strategies that are compatible with EMU traction and don't reduce line capacity by increasing emergency braking distances. Apparently, that's a non-trivial problem or Deutsche Bahn would be using such a system in Cologne today. What's available on the market may be suitable for coasting through at speed, but in a station throat braking and acceleration are required.
Note that TJPA has no authority to de facto make train vendor decision for Caltrain and/or CHSRA, nor should it. All I'm saying is that as long as the three curves in the approach remain this tight, Caltrain and CHSRA will have no choice but to somehow mitigate the inevitable consequences. If the aural experience of the SF train station is negative, ridership will suffer.
- Consider harmonizing the platform height of Caltrain locals at HSR levels and assigning platform tracks on real-world demand, eliminating the need for tail tracks. Optionally, extend the southernmost platform tracks (#21+22) as far as Main Street as well.
- Irrespective of platform height harmonization, consider letting Caltrain run strictly regional HSR trains between SF and SJ as long as there is spare capacity on the HSR tracks in the SF peninsula.
- Eliminate the 4th & Townsend station from the DTX tunnel. Instead, have tracks descend at 3.5% gradient immediately after crossing Mission Creek through the curve near 7th & Townsend. Use switches to create an underground station with two short platform and two through tracks on 4th & King property. If absolutely necessary, stack additional platform tracks on top of those.
- Limit tunnel to two tracks between 4th & Townsend to 2nd & Folsom and use a single TBM to excavate that. Deploy crossover switches in the last section, followed by two Y plus one reverse Y switches to branch into three platform connector tracks. Just north of Tehama, use switches and diamonds to implement turnoffs toward the TTC train box. Dead-end the through tracks for now.
- Negotiate HSR and Caltrain ridership conditions that would require the city of SF to kick off a third phase of the TTC project, subject to a third EIS/EIR process. This would implement an "auxiliary terminal" featuring three additional full-length platform tracks at level -2 under 2nd Street between Market and just south of Howard. This would be intermodal with the existing Montgomery BART/SF Muni at Market plus city and GG transit buses at 2nd/Mission and also permit a future second BART line along Mission at level -3. Note that the available width under 2nd, including sidewalks, is 75 feet.
A second pedestrian connector passage, similar to the first but above e.g. Minna Street between 1st and 2nd, would be included in the scope of the EIS/EIR auxiliary terminal.
- The auxiliary terminal concept would be considered part of the TTC but remain unfunded for the time being. Let's see Caltrain and HSR actually achieve something approaching their rosy ridership forecasts first.
View Aux Terminal under 2nd in a larger map
NOTE: I've edited the map to move the phase 2 pedestrian passage from Main to Beale Street since TJPA already studied that alignment in April 2007. It has languished for lack of $105 million in funding, something the HSR project can and IMHO should help provide if it ends up using TJPA's TTC train box as designed.
Links to previous posts related to the Transbay Terminal on this blog:
Sep 21 CHSRA Staff Recommendation on Phase 2 Stimulus Funding
Sep 18 Deputy AG Letter Supports CHSRA's Transbay Position
Sep 16 What's Up With The Transbay Terminal/
Aug 25 California Applies For $1.1 Billion In HSR Stimulus Funds
Jun 06 SJ, SF Mayors Push Transbay, Diridon, Caltrain Upgrades
Apr 29 New Transbay Terminal Renderings
Apr 14 Quentin Kopp on Transbay Terminal
Apr 05 Transbay Terminal Redux
Mar 24 BruceMcF On Transbay Terminal
Mar 14 Your Weekend Transbay Terminal Update
Mar 03 Tight Squeeze At Transbay Terminal?
On Clem Tillier's excellent Caltrain-HSR Compatibility Blog:
Sep 19 Platform Height
Jun 13 Future Transbay
Jun 06 Build Me A Train Box
Mar 25 Focus On: SF Transbay Transit Center