16 December 2010

Progress at Transbay?

The many failures of the Transbay Transit Center design, as a train station, have previously been pointed out (see here and here). A November CAC briefing on the latest design iterations of the platform levels finally shows some incremental progress. After digging that $400 million hole, we may actually find signs of intelligent life down there.
  • Caltrain tracks are moved to the northwestern edge of the train box, closest to downtown. While this change was advertised to avoid the foundations of the high-rise at 201 Mission St, (TJPA headquarters!) a better reason is that Caltrain ridership at Transbay will likely exceed anything HSR can muster. In this case, two wrongs have inadvertently made a right.

  • With Caltrain tracks switched around, the future plans for tail tracks are now infeasible, and rightly so because underground tail tracks are the most expensive way you could possibly think of to park trains while they are not producing revenue. Again, two wrongs (the desire for tail tracks, and the competing desire for ramrod-straight platforms) make a right (no more tail tracks!)

  • A new entrance is provided on Beale Street, with an escalator bank perpendicular to the train box, reaching towards downtown. Caltrain passengers can directly access the Caltrain platform without any scenic detours through the rabbit warren of sequential, airport-like functional spaces intended for HSR, which make absolutely no sense for the daily commuter. This new entrance is a big step forward because it suggests for the first time a concern with minimizing the overall travel time of Caltrain passengers. If it's not too much to ask, two more such perpendicular access points should be added at Fremont and 1st streets (better yet: emerging north of Mission, so pedestrians don't have to wait to cross those busy intersections.)

  • Additional curved turnouts seem to have sprouted in the station throat, thankfully not labeled "emergency crossover", suggesting the possibility of improvements in operational efficiency and flexibility--although once again, nothing would beat a common platform height.
Happy Holidays to everyone.

26 November 2010

Future EMU

The newest automobiles are shown in Paris, Tokyo and Detroit. The latest aircraft are shown at Farnborough and Le Bourget. What about the newest passenger trains? That show, in Berlin, is known as Innotrans and provides a window on the latest evolution in the type of EMU (electric multiple unit) trains that Caltrain is pursuing. One of the future train concepts shown at the recently-concluded Innotrans 2010 is Bombardier's Omneo product platform, ordered in large quantities by French regional transportation authorities and due to enter service in mid-2013. That order is in itself noteworthy, because Bombardier beat French firm Alstom, the incumbent provider of the previous generation of double-deck regional trains, on its home turf.

Tailored slightly for U.S. dimensions, a possible Caltrain Omneo concept is shown in the sketch above. The following key features set it apart from the 1990s-vintage EMUs that feature in Caltrain's electrification plans--the very EMUs that the Omneo is set to replace:
  • Articulated design. The wheels are placed between, rather than under each train car, leading to a smoother ride. Gangways between cars, traditionally cramped, dark, loud, shaky and unwelcoming places, are transformed into full-width, seamless passages that turn the train into one continuous space. Vehicle systems (traction equipment, air conditioning, etc. shown in dark gray in the figure) are moved entirely out of passenger spaces, below the floor and above the ceiling. With inter-car gangways and systems cabinets gone, open sight lines promote a sense of space and safety inside the train.

  • A usable amount of high-floor space. Bi-level EMU cars are always a configuration challenge, since passenger spaces must fit around numerous vehicle systems while still providing full ADA accessibility. Accessibility means that wheelchair spaces, bike spaces and accessible toilets must all be provided on the door entry level. Traditional bi-level cars do not provide sufficient room for all these amenities in the high-floor vestibule areas over the wheels, and thus typically board on the lower level where more contiguous space is available. Articulation gets rid of this design constraint.

  • High-level boarding. While the traditional bi-level EMU architecture tends to allow boarding only on the lower floor, this concept features a 1220 mm (48 inch) boarding height that would be compatible with high-speed rail platforms. The Omneo is offered in 550 mm, 760 mm and 920 mm boarding heights, but additional vertical clearance available in the U.S. makes a 1220 mm floor height feasible. A shared platform interface between Caltrain and HSR presents enormous operational advantages by allowing any train to access any platform, especially at San Francisco Transbay.

  • Dual, High-Low Doors. To allow a gradual transition from today's 8-inch platforms to 48-inch HSR-compatible platforms, each vestibule features two doors, one for each height. While this temporarily restricts door capacity during the transition period, the modular door assemblies provide for easy reconfiguration to 100% high platforms once the transition is complete. Dual height doors are not unprecedented.

  • Extra wide interiors. The articulated design shortens car bodies from the traditional 26 m (85 feet) to just 10 or 15 meters. Shorter cars, for a given loading gauge, can be made wider than longer cars. A U.S. spec Omneo car body could be 3.1 m (122 inches) wide in the 15-meter double deck section, and 3.15 m (124 inches) wide in the 10-meter single deck section, all within AAR Plate F. That's 4 and 6 inches wider, respectively, than today's Bombardier bi-level cars used in Baby Bullet service. Such wide interiors might enable comfortable 5-abreast seating.
Bombardier vs. Bombardier

It's instructive to compare the Omneo EMU concept to another product in Bombardier's portfolio, the bi-level commuter cars that Caltrain operates for its Baby Bullet service. The diagram at right shows a direct comparison of a Caltrain car to a pair of Omneo cars of roughly equivalent length.

At three seats abreast, an 11-unit Omneo train measuring 145 m (475 ft, a bit shorter than a 493 ft Baby Bullet train) accommodates 695 seats and 48 bikes, compared to 674 seats and 48 bikes for a Baby Bullet. With a two-abreast seating plan making use of the extra width for aisles and standees, the Omneo would still accommodate 590 seats (not counting 48 flip-down seats.) Using a metric that Caltrain is fond of, seats per unit length of train, here's how it stacks up:
  • Baby Bullet: 1.37 seats/ft or 4.5 seats/m (including locomotive)
  • Omneo 3+2 seating: 1.46 seats/ft or 4.8 seats/m
  • Omneo 2+2 seating: 1.24 seats/ft or 4.1 seats/m
These figures show that an Omneo-like EMU would achieve rough parity with the Baby Bullet in terms of seating density. Of course, as we've discussed before, it's not all about seats... standees are passengers too, if you give them somewhere comfortable to stand.

Innovative Design Enables Platform Height Compatibility

This article is not intended as an endorsement of Bombardier's products; their Omneo train merely serves as an illustrative example. Other manufacturers (Alstom, Siemens and Stadler) aren't standing still, and are also increasingly focused on articulated EMU designs with innovative and flexible interior packaging. In light of these new technological developments, Caltrain's relentless pursuit of 20-year-old double-deck EMU designs locked into a low-platform architecture seems downright archaic.

Cutting-edge European vehicle designs will not compromise the basis of Caltrain's FRA waiver, and might help achieve one of the key tenets of compatibility: a common platform interface for HSR and Caltrain, without billions of dollars and years of platform reconstruction up front. The trains can come now, as part of the electrification project, and the rest can follow later as time and money allows. What is required is a little bit of forward thinking to future-proof the system and enable any train to use any track to access any platform.

18 November 2010

Still No Compatibility In Sight

The high-speed rail authority's program management team, of Parsons Brinckerhoff Quade & Douglas, recently published an Operations & Maintenance Concept for peer review by the many foreign HSR operators with which the California High-Speed Rail Authority has signed collaboration agreements.

Besides regurgitating much of the same information already available in the various EIRs and technical memoranda, the peer review document states a number of operational assumptions that have far-reaching implications for the peninsula rail corridor. The first one on the list:
1. The HST system is assumed to operate on dedicated tracks, independent of any other passenger or freight rail services, except in the following locations:

a. Peninsula Corridor – approach tracks leading to the two terminals at Transbay and 4th and King Streets (shared between CHST and Caltrain commuter trains)
Note the added emphasis, that only the approach tracks would be shared, namely north of Brisbane. And then, this:
8. (...) Train operations at the San Francisco end of the network will be complex, linking the two terminal stations, each with mixed HST and commuter traffic, with the San Francisco‐area storage and maintenance yard, as well as the four‐track main line that has high‐speed trains on two dedicated tracks and commuter trains on the other two tracks.
While the document does briefly entertain the alien notion of shared platforms, as well as a "proof-of-payment" fare system where POP must be provided in the paid area of the station (talk about not getting the concept!), what is abundantly clear here is that high-speed rail is being planned on the peninsula without regard to integrating operations with Caltrain--in flagrant disregard of the MOU with Caltrain, and of many successful shared corridors around the world, including even in New Jersey. In this vision, Caltrain is confined to two tracks, and relegated to the role of an operational nuisance on the approach into San Francisco. Any synergy that might arise from Caltrain express trains sharing tracks with high-speed trains is wasted.

Change The Assumptions, Before It's Too Late!

These operating assumptions have dire implications for local commuter rail service on the peninsula.

Caltrain has so far demonstrated a total lack of ambition on the operations front, and has utterly failed, ever since Proposition 1A passed in 2008, to think outside of the two-track box known as Caltrain 2025. There are ways to provide better service with fewer trains, provided that integrated planning is performed up-front by the Peninsula Rail Program, pursuant to the memorandum of understanding (which the above operating assumptions directly contradict).

The high-speed rail program management team is also uninterested, in the first place because their charter is to provide high-speed long-distance service, not commuter service, and secondly, because the same firm built BART. While this can only be alleged, Parsons Brinckerhoff Quade & Douglas likely has zero interest in improving Caltrain, and every financial interest in receiving another several billion dollars of taxpayer's money to complete BART's manifest destiny to ring the Bay.

Foreign peer reviewers will have little interest in questioning the operational assumptions, since doing so might rock the boat and compromise their future ability to obtain contracts to build and operate California's system.

So just who does that leave to do the right thing, hopefully before any concrete is poured?

Residents and city governments should push hard for Caltrain to integrate its operations with the high-speed rail system, going for maximum flexibility, striking the appropriate balance between local and long-distance services, and enabling the optimal allocation of scarce resources, (such as track capacity at rush hour, platform space at terminal stations, station area footprints in developed areas, etc.) in response to actual demand patterns as they develop. For planning purposes, that means any train should be able to use any track, and stop at any platform.

If peninsula communities are going to bear the considerable disruption of HSR construction and operation, they should have every interest in getting at least a little bit of trickle-down service benefits in return. Otherwise, they may become the rail equivalent of fly-over country.

(thanks to CARRD for obtaining the O&M peer review document)

01 November 2010

News Roundup, World Series Edition

Supplemental AA Supplement: The CHSRA posts the latest round of tweaks to the peninsula alternatives analysis. The updated report is due in November. (Note: this briefing was abridged by the CHSRA, shortly after being posted. The link is to the original slides that were removed from the CHSRA website.)

The Money Goes Poof: since the Feds have specifically ear-marked $715 million in HSIPR funding for the Central Valley, the winner-take-all, four-way horse race between Merced - Fresno, Fresno - Bakersfield, Los Angeles - Anaheim, and San Francisco - San Jose is for all intents and purposes decided before the CHSRA board even gets to vote. Bottom line: SF - SJ is out of the running and will not receive any of the $2.25 billion in ARRA stimulus funds. That has huge implications on process: the rush to beat a 2012 shovels-in-the-dirt deadline is gone.

Ray Writes Anna: the Secretary of Transportation writes a letter to assure Congresswoman Eshoo and concerned peninsula residents that "no final decision has been made regarding the design of this segment, and DOT must approve any final alternative in order for it to receive Federal funds. As long as this process is underway, we cannot prejudge the final outcome." In short, he claims there is adult supervision and the mad rush (now moot--see above) for early federal funding will not preempt due environmental process.

Anna Writes Ray: the Congresswoman
replies, profusely thanking the Feds for their oversight and the few crumbs thrown our way (a paltry $16 million, nominally ear-marked for re-arranging the platforms at San Francisco's 4th & King station) ...

... and asks for CBOSS Pork: Eshoo asks that the $16 million be re-allocated to the CBOSS project. She pointedly states "We can assure you that the PTC project is not a "throwaway" that would benefit only Caltrain and require replacement or costly upgrade when HSR is built."

If only that were true.

If only the secretary could hear from people who didn't drink the CBOSS Kool-Aid... for example, by reading Caltrain's own crystal-clear statements that the design of CBOSS will not take HSR into account. Or simply typing "CBOSS Caltrain" into Google. Recall that CBOSS is (a) an overlay system (that's what the 'O' stands for) that cannot function on its own as a stand-alone HSR-capable signaling system, (b) is designed primarily for freight trains, not HSR, and (c) is currently vaporware. For the $230 million they are trying to marshall for this science project (a massive sum with an elastic upper bound, to be exercised via contractual engineering change orders) they could simply install ERTMS, the emerging worldwide HSR standard, at very little cost or schedule risk.

Message to LaHood and Eshoo: now that wouldn't be a throwaway.

16 October 2010

Station Design 101

If you're the poor sucker in charge of designing a mid-peninsula high-speed rail station, here's what you must do: start with the ridership estimates for full 2035 system build-out, and apply Technical Memo 2.2.2 (station design policy) as handed down from above by Parsons Brinckerhoff, the firm in charge of the HSR system design. Table 6.1 has all the relevant formulas that you'll need to size the outer concourse, controlled waiting areas, how many restrooms, etc. All that remains is to plug and chug the formulas and presto, you've got yourself a station.

The result of this formulaic approach to station design can be seen in the recent sizing study for a potential mid-peninsula station at Mountain View, which is very similar to the notions also being entertained for Palo Alto or Redwood City. Key statistics: about 8000 daily HSR boardings, 67000 square feet of floor area (not including platforms), and 3000 parking spaces.

Implicit Requirements

While the technical policy and system requirements do contain a variety of clearly stated requirements concerning station design, many of the requirements are not stated, but instead taken for granted. They are implicit requirements. The following is an attempt to make them explicit:
  • The station shall funnel every passenger through a sequence of functional spaces that broadly mimic an airport.

  • The station shall be divided into a public concourse and an access-controlled area requiring possession of a valid ticket.

  • The station shall have a mezzanine, a large access concourse located above or below the platforms that provides the "necessary" floor area to funnel passengers from a grand station entrance (complete with "entry plaza") through "check-in", shops and restaurants, and possibly "security" to a "gate".

  • The HSR platforms shall be used exclusively by high speed trains, and may not under any circumstance be shared with Caltrain. The same track and platform edge may not be served by both HSR and Caltrain. The same platform at opposite platform edges may not be served by both HSR and Caltrain.

  • The HSR platforms shall be fully access controlled with high fences, even if such fence is used to segregate the HSR platform from an adjacent Caltrain platform.

  • Passengers transferring between HSR and Caltrain shall use escalators and transit via the mezzanine. Maximum vertical circulation is encouraged, and convenient cross-platform or same-platform transfers are explicitly disallowed.

  • The station shall have gargantuan amounts of automobile parking (1000 spaces at the station, and another 2000 spaces within 3 miles).
None of these "requirements" make any sense, except to maximize the size and cost (and profit) of building such grandiose but operationally dismal infrastructure. What is being envisioned here is not an integrated rail network, but well and truly a flight-level zero airline.

Another Way

It doesn't have to be this way. In France or Germany, any bum off the street can drag a large suitcase onto a high-speed train five minutes before departure without ever passing through a security check or a fare gate. Tickets are checked on board, using what's known as proof-of-payment or POP: if you can't produce a valid ticket when asked, you are issued a citation. POP obviates all this sterile-area gated fare-paid-only nonsense, with enormous simplification of the process of getting from point A to point B.

Is POP a gaping security hole? Not if you consider that bombs brought on board high-speed trains are a rather unreliable way to achieve mass carnage. That's why over several decades, such an attack has only been carried out once, and then rather unsuccessfully. The target environment will necessarily be far richer over on the Caltrain platform. Terrorists in Madrid knew this when they attacked at Madrid's main HSR terminal; all their bombs went off on packed commuter trains. So, a rational evaluation of threats (one not based on security theater) leads to the conclusion that HSR need not look like a BART fortress on steroids.

In Europe, land of POP, commuter rail and HSR routinely share platforms, leading to far more efficient use of space inside stations. For example: Paris, Berlin, Karlsruhe, Hamburg (on a sacrilegious curved platform, no less!), Brussels, and dozens more.

The graphic below shows the differences between the gargantuan mid-peninsula dial-a-station proposed by the CHSRA (and rightly rejected by Mountain View, Palo Alto and Redwood City) and a mid-peninsula station of far more modest proportions, that could be achieved without any loss of functionality provided that the following simple requirements are adopted:
  • HSR shall use barrier-free fare control
  • Caltrain shall use the same platform height as HSR
  • Stations shall allow any train to use any track to access any platform
  • Stations shall minimize vertical and horizontal circulation needed to access any train
Appropriate station design requirements have an enormous effect on the resulting designs, with overall width dropping from an elephantine 265 feet (as depicted in the sizing study) to a more manageable 122 feet.

At a time when the HSR project is increasingly under attack for being insensitive to peninsula communities, perhaps a reevaluation of station requirements would improve the chances of someday achieving a context-sensitive solution. Mountain View, for example, could have the highly-effective, low-impact intermodal station previously described in this space.

06 October 2010

Juicy CBOSS Tidbits

UPDATE: the Q&A with prospective bidders continues. The latest round includes these gems:
Q #31: The RFP addresses HSR. What assumptions should the proposer make in order to address HSR requirements?

A: Evaluation of the potential for the proposed solution to meet future HSR needs will not be part of the proposal evaluation.

Q #43: [Caltrain] states that "the system will be required to be interoperable with the train control system selected for HSR operation throughout the California High Speed network." Since this train control system has not been identified, how can the contractor ensure that their system will be interoperable by the 2015 implementation date?

A: The Caltrain PTC system must be interoperable with existing tenant railroads by Dec 2015. HSR is not an existing tenant railroad.
There. Just in case there remained even the shadow of a doubt: Caltrain couldn't care less about interoperability with HSR, but is focused like a laser on interoperability with Union Pacific freight trains, a.k.a. "tenant railroad."

Caltrain is betting all its chips on the AAR's Interoperable Train Control (ITC) project, an industry-wide consortium effort to stonewall and delay the federal PTC mandate. If there is any doubt about what the AAR (representing the big freight railroads) thinks about PTC, read their litany of complaints and ask yourself just how likely it is that ITC will be completed on time--regardless of the law. Expect the AAR to slow-walk PTC just as the Europeans run rings around us worldwide!

ORIGINAL POST: Caltrain's planned Positive Train Control system (known as CBOSS) has been out to bid for a little while now, and the Request For Proposal process is continuing with some back-and-forth Q&A between Caltrain and prospective bidders in advance of the November 3rd deadline.

The latest volley of questions and answers includes question #20 from an astute prospective bidder:
What assumptions should me made in terms of HSR? (Interoperability, Operations, sharing track, etc.)
Caltrain's official response:
Under current RFP Scope of work, HSR Operations is not considered for this phase of PTC implementation. Public information is available via HSR webisite. (sic)
It's October 2010, and Caltrain still considers high-speed rail as an afterthought. Shall we give them another raise?

Also, just where is the funding for CBOSS going to come from, and is the undetermined funding source why Caltrain refuses to change the wording of the contract payment terms from "will endeavor to pay" to "shall pay" (see question #11) ?

26 September 2010

Train Noise Calculator

UPDATE: noise calculator spreadsheet is now available in both .xls (Excel 2003) and .xlsx (Excel 2007) formats.

The generation, propagation and perception of noise is one of those fields where concepts are deceptively simple and yet devilishly complex. Anybody can buy a sound level meter at Radio Shack, but that doesn't make one a noise expert any more than buying a calculator makes one a math whiz. Thankfully, the FRA publishes a well-written guidebook on High-Speed Ground Transportation Noise and Vibration Impact Assessment that describes a standard methodology for determining noise impacts from new high-speed rail projects. While this guidebook was published in 2005, the physical laws of acoustics remain the same as always.

Despite citing the FRA guidebook, there is little evidence in the CHSRA's program-level EIR noise and vibration chapter and its appendices that the source-path-receiver model framework described in the handbook has actually been applied. Impacts are broadly classified as high, medium or low, and crudely bumped down by one level on the peninsula (from "high" to "medium") because horn noise would be eliminated from more than 40 grade crossings.

To make the issue of noise impacts more accessible to the layperson, an implementation of the FRA noise impact assessment model is provided in the form of a train noise calculator spreadsheet (45 kB Excel 2007 .xlsx file or 140 kB Excel 2003 .xls file, no macros, made virus-free on a Mac.) Before playing with this, it's probably best to study up on the basics of noise in the FRA guidebook as well as CARRD's compilation on noise pollution to tell your dBA's from your Ldn's.

By crunching the FRA parameters and equations behind the scenes, the spreadsheet allows a rapid evaluation of noise impacts (None, Low, Moderate, Severe) as shown in the screenshot at right. The blue circle represents the project's impact, and you can see how it moves around the noise impact diagram based on:
  • Train speeds (anywhere from 20 mph all the way up to 220 mph)
  • Train length
  • Train frequency (both peak frequency, and nighttime traffic)
  • Train type (diesel, electric, maglev)
  • Track configuration (elevated, at-grade, trench...)
  • Screening effects from intervening rows of buildings
  • Distance from the tracks
  • Property use (residential, institutional, outdoor...)
  • Existing noise environment (suburban, urban, etc.)
The spreadsheet also implements a twist for the peninsula: the HSR project would not only add high-speed trains but also replace diesel Caltrain with somewhat quieter electric trains. The spreadsheet calculates the effect of the substitution of one type of traffic for another, and accounts for some unusual scenarios where the HSR project may generate less noise than the existing at-grade, diesel Caltrain.

Some interesting findings, which one is free to experiment with in the spreadsheet:
  • Elevated viaducts, as currently proposed, are twice as loud (+9 dBA) as elevated berms at the train speeds envisioned on the peninsula, everything else being equal. Viaducts amplify rolling noise because they are hollow structures that act as a resonating chamber. Belmont and San Carlos might be well-advised to leave their berms as they are.
  • At-grade tracks can be made half as loud (-10 dBA) with a noise barrier, when train speeds are in the 100 - 125 mph range proposed for the peninsula. Noise barriers become less effective as train speed increases and noise becomes dominated by aerodynamics, but here on the peninsula, they would probably do just fine.
  • Trenches are extremely effective at shielding train noise; they are overkill as far as noise mitigation is concerned. With a trench, even very high levels of traffic (several hundred trains a day) would create less noise than Caltrain does today. The trench need not even be covered for this benefit to be realized.
  • The proximity to an existing grade crossing with horns has a significant effect on the severity of the impact from the HSR project, as pointed out in the EIR noise chapter. A suburban residence within 500 ft of a grade crossing experiences ambient sound levels twice as loud (+10 dBA) than a suburban residence located away from grade crossings with horns. Since the existing noise level is the basis against which the noise added by the project is evaluated, areas near grade crossings can be expected to rate a lower impact. Nevertheless, not all areas along the peninsula corridor are close to a grade crossing.
  • Not surprisingly, Caltrain's fantasy schedule (10 tph peak, 162 trains/day) combined with HSR's fantasy schedule (10 tph peak, 6 tph off-peak, 228 trains/day) results in ~5 dBA worse noise impacts than a more realistic traffic level of 6 tph Caltrain and 4 tph HSR.
  • Out in the central valley, urban areas with ~150 trains/day blasting at 220 mph on concrete viaducts would experience severe noise impact within ~500 feet on either side of the tracks. Suburban and rural areas would experience even wider areas of noise blight, especially if the tracks are built on viaducts.
Noise is one issue; its evil twin, ground-borne vibration, is a subject for another day. In the meantime, suggested improvements to the train noise calculator spreadsheet are most welcome.

15 September 2010

That Burning Smell

There's a burning smell at Caltrain headquarters, from the smoldering tensions over high-speed rail on the peninsula. Caltrain CEO Mike Scanlon tries to triangulate a dicey situation with a statement to the public and a letter to his counterpart at the CHSRA. Let's review the state of play:
  • Facing a catastrophic shortfall in its operating budget for fiscal year 2012, Caltrain needs every ounce of good will it can get from peninsula communities in order to survive as a service and as a bureaucratic entity. All this talk of 80-foot wide viaducts tearing through residential neighborhoods is not helping one bit.
  • Caltrain's electrification project, cast for years as the key to future improvements in the system's operating bottom line, is being held hostage by (a) uncertainty over the proper phasing of the electrification project with respect to HSR construction, (b) threats of lawsuits over a somewhat stale EIR that tiptoes around the HSR issue, and (c) the funding package unraveling at the seams, on the widely held but mistaken expectation that HSR will pick up the tab.
  • Caltrain's $230 million reinvent-the-wheel PTC science project, mandated by the FRA as a sine qua non pre-condition to electric operation, has gone out to bid on a wing and a prayer with no clear source of funding identified other than the remote chance that the peninsula HSR project might receive the entire federal grant allocated for the statewide HSR system.
  • Caltrain's own guy, Bob "Father of the Baby Bullet" Doty, propelled into the driver's seat of the joint Caltrain - CHSRA Peninsula Rail Program, valiantly ran interference with peninsula communities, and must now be wondering if the steering wheel really is connected to the wheels of this particular bus.
The surest sign of a thorny situation is that stakeholders keep calling for the project to be "done right," the touchstone platitude that is always trotted out when people start to get hot under the collar.

Reset Button

Another recurring buzzword is "reset button." Californians for High Speed Rail wants to hit one reset button. Congresswoman Anna Eshoo wants to hit another reset button.

What about hitting a big red reset button at the Caltrain bunker in San Carlos?
  • Ditch the weak operating plan proposed as part of Caltrain 2025, and plan for smoking-hot corridor operations. A clockface timetable with a mid-line standing overtake, more than any other Caltrain improvement, promises to increase revenue while keeping operating costs under control, because it requires fewer trains and fewer crews to operate a service that will make the Baby Bullet look like a Model T.
  • Phase the quadruple tracking for HSR and start by building a modest four-track mid-line overtake facility from Redwood Junction to just south of downtown San Mateo. This avoids most of the NIMBY controversy while delivering the highest possible corridor throughput for Caltrain express service as well as the initial HSR services.
  • Ditch CBOSS and specify an off-the-shelf PTC standard that can be expanded to the statewide HSR system. Such a system already exists, and is mentioned dozens of times throughout the CHSRA's system requirements with the contractually-delicate phrasing "The CHSTP train control system will demonstrate Functional and Technical Requirements similar to ERTMS but the System Requirements are being written without specifying an ERTMS system. It is accepted that an ERTMS system may eventually be proposed and accepted." Bonus: HSR funds might pay for Caltrain's PTC.
  • Address the issue of level boarding once and for all. To make the most efficient use of San Francisco's new Transbay Transit Center, it is crucial that Caltrain and the HSR system adopt a common platform interface. The mantra ought to be "any train, any track, any platform". So far, there is not a peep from Caltrain.
While it can't be confirmed, the reset button is possibly located right under Mike Scanlon's desk.

12 September 2010

Belmont Shoots the Moon

The Belmont City Council is crafting a resolution (see original draft, and revised draft to be considered on 9/14) supporting the reinstatement of a cut-and-cover trench option for the high-speed rail authority's San Francisco - San Jose Draft Project EIR.

Underground tracks, favored by the city, were dropped from further consideration when the CHSRA published its Supplemental Alternatives Analysis on August 5th. That action left Belmont (and neighboring San Carlos) with only a single option to be carried forward for further study in the EIR: a tall viaduct. This viaduct is featured in crude renderings and a YouTube video posted by the city.

Belmont is the only member of the Peninsula Cities Consortium that did not have a trench or below-grade option carried forward for detailed study in the EIR, which has city officials fuming.

All Those Grade Crossings In Belmont

The Supplemental AA has caused quite an uproar on the peninsula, especially in the member cities of the PCC, largely because of the vertical alignment options proposed for the four-track corridor. The vertical alignment may need to be changed, requiring either raised or lowered tracks, in order to eliminate about 45 grade crossings along the peninsula corridor that would otherwise have to be closed. These changes are necessary because the California Public Utilities Commission, which regulates grade crossings and pursues a stated policy of reducing the number of such crossings, is exceedingly unlikely to allow four-track grade crossings, much less in a dense suburban environment, regardless of train type or train speed.

One might reasonably assume, then, that the range of vertical options feasible for Belmont would depend solely on the locations and constraints imposed by the grade crossings that currently exist in Belmont. The trouble with this assumption is that the number of grade crossings in Belmont is... Zero.

The existing tracks run through Belmont on a retained fill embankment (shown in photo at left, and known in some quarters as a Berlin Wall) over Harbor Blvd and Ralston Ave. These grade separations were built starting in 1996, opened in October 1999, and did not cut off any pre-existing (legal) access across the tracks. The berm is now perceived as a community division, and prompted the official request to study design options that would enable its removal.

Why a Viaduct?

The Belmont viaduct is an example of the Context Sensitive Solutions process producing an unwanted outcome.

From its very first scoping comments, Belmont expressed misgivings about the berm and requested enhanced connectivity and mobility, in the hope of obtaining a tunnel paid for with OPM (Other People's Money). Taking into account the feedback provided by the Policy and Technical Working Groups at a series of meetings attended by Belmont officials, the Supplemental Analysis Report substituted a tall viaduct for the existing berm because "the Berm option does not enhance connectivity and mobility as well as an aerial viaduct option."

If Belmont disagrees with this outcome, if the city believes the viaduct is not better than a berm, and if this business about connectivity and mobility was all just a colossal misunderstanding, then the berm will simply be expanded to four tracks. The berm is a "fact on the ground" and its visual impact, once all is said, done and litigated, will not be counted against the high-speed rail project. That is the likely outcome if Belmont becomes any more strident in its demands for a tunnel.

09 September 2010

Peninsula Rail Corridor Road Crossings

Click to enlarge, or better yet, download the PDF (57 kB)

This was the snapshot as of 2010.  For how this configuration might evolve over coming decades, please see Grade Separation: the Decadal View

28 August 2010

The Prescriptive Framework: System Requirements

A System Requirement is a statement that identifies a necessary attribute, capability, characteristic, or quality of a system in order for it to have value and utility to a user. The entire engineering effort for the California high-speed rail system is prescribed by a long list of technical requirements, which taken together form the system specification. The requirements are prepared by the program management team at Parsons Brinckerhoff, and cover every detail down to the allowable shades of red for the train's tail lights.

The Palo Alto grassroots group CARRD recently made a public records request for this important material. Thanks to their persistence, the system requirements have now been made public:
The document that is likely to be of most interest is the 961-page "kitchen sink" which also contains background information on how each requirement was developed:
A large portion of the requirements is a hodgepodge of existing FRA regulatory requirements (Title 49 of the Code of Federal Regulations), AREMA (U.S. industry) recommended practices, and TSI (European Technical Standards for Interoperability) requirements. The European requirements are featured prominently because there is no existing regulatory framework for very high-speed rail in the United States, and California must blaze the regulatory trail.

As the high-speed rail system comes under ever-increasing scrutiny, these requirements will reveal where and why the CHSRA and its prime contractor (Parsons Brinckerhoff Quade & Douglas) might resist design suggestions made by communities along the rail corridor.

19 August 2010

Another Wheel Gets Squeaky

With the recent release of the Supplemental Alternatives Analysis for the peninsula high-speed rail project, Redwood City has found itself with only one design alternative carried forward: an elevated four-track viaduct through downtown. This does not sit well with the mayor, who fired off a sternly worded letter to the Peninsula Rail Program, as reported in the Daily Post.

The letter points out that trenches are being carried forward only in those cities that have vigorously opposed the high-speed rail project, unlike Redwood City. The squeaky wheel seemingly gets the grease, and Redwood City feels left out.

The letter is noteworthy because Redwood City has not been at the forefront of HSR opposition so far. Councilwoman Rosanne Foust, a former mayor, is a strong supporter of high-speed rail and serves as CEO of SAMCEDA, the San Mateo County Economic Development Association. One of SAMCEDA's initiatives is the Alliance for Sustainable Transit and Jobs, a pro-HSR lobbying group.

Long-Standing Plans For An Elevated Station

The cover page of Redwood City's controversial 2007 Downtown Precise Plan (set aside in 2009 after litigation) prominently featured the architectural rendering of a downtown elevated train station shown at the top, similar to what the HSR project now proposes. The plan stated that "the preference and assumption has been that the tracks will be elevated above grade, and a new train station will be centered on Depot Circle and the pedestrian connection to Sequoia Station and El Camino Real. This elevated railway will be carefully designed to become one of Downtown’s major assets." The draft New Downtown Precise Plan, published in March 2010, also assumes an elevated railway, as revealed in Book 2.3, which features the diagram of a railroad frontage lane shown at left.

Does that make Redwood City's new-found stance a bit disingenuous?

08 August 2010

Alternatives Analysis Analysis, Part 3

The Supplemental Alternatives Analysis for the peninsula corridor reveals some key engineering choices being made. That tunnels would be taken off the table was never in doubt: tunnels are nothing but trouble. The only tunnels now left are those that have a mountain. Well, almost... as we'll see below.
  • Freight grades: we were told all along that 1% is the limiting gradient for heavy freight. Not so in Palo Alto, where there is a 2% grade shown in the track profiles (page 15). Recall that the steepness of a grade has no impact on passenger comfort, frequent references to roller-coasters notwithstanding. (This question of dynamics seems to confuse civil engineers, who deal mostly with statics.) If a freight train can handle a 2% grade in Palo Alto, it can certainly handle a 2% grade anywhere else; that's the concept of ruling grade. Considering that steeper grades would greatly reduce the footprint of any elevated section, for example, the massive Mary Avenue rail overpass in Sunnyvale shown on page 18, why are 2% grades not the rule?

  • Rail yard: the rail yard in Brisbane, the closest-available 100-acre parcel near San Francisco, is on a direct collision course with the redevelopment plans for this area. This may end up as the largest land transaction in the peninsula HSR project. Curiously, the yard is planned on the east side of the tracks, opposite the historical site of the Southern Pacific rail yard.

  • Berms be gone: Belmont and San Carlos get their grade separation berms removed and replaced by a gratuitously tall viaduct, with the tracks 20 feet higher than today's berms. That doesn't go over well with the mayor of Belmont. Prediction: when all's said and done, Belmont and San Carlos will be begging for their berms to stay essentially as they are.

  • Blank-check engineering: Millbrae gets some ridiculously massive civil works in order to shoe-horn a fourth track under the ill-configured station. The plan features a 2.5-mile long tunnel (see track profiles, page 8), diving 75 feet below grade in order to duck under the Hillcrest Blvd underpass. Cross sections are also provided (see pages 13 and 14). There are two design options that are likely to be far cheaper and less disruptive to construct:

    1. Convert the western-most BART track to Caltrain (see Option D in this diagram). While this requires minor surgery on the existing BART station, and may require an exception to side clearances (e.g. a steel crash barrier to separate BART from Caltrain), no digging would be required.

    2. Put the Millbrae BART platforms underground. The tunnel already exists, emerging right before the station.

    When the alternative is a 2.5-mile tunnel with an underground station mezzanine, which would likely require partial demolition of the existing station structure all in the name of leaving untouched the under-used BART parking tracks, one is left wishing that these issues had been thoroughly examined and addressed in the AA.

  • Slimmer sections: Many cross-sections have gone on a diet, narrowing down from the previous elephantine proportions to more realistic dimensions. The four-track retained-fill berm is slimmed down to 78 feet (wall to wall), the elevated viaduct is down to 78 feet, the trench is down to 76 feet (fence to fence). The at-grade alignment remains at 93 feet (fence to fence), but only because the fences are set back 11 feet from the (perfectly safe-to-touch) overhead catenary masts. The eminent domain panic set off back in March was premature: the tracks will mostly fit within 80 feet, a width already available along 88% of the corridor.

  • Fatter bridges: box-beam elevated structures have a depth of nearly 10 feet (measured from the bottom of the bridge deck to the top of the rails), compared to 5 feet as routinely practiced today, for example on the Belmont - San Carlos grade separations. That means future grade separations must lift the rails at least 25 feet above the road surface, compared to about 20 feet today, with attendant increases in the size of the bridge approaches. Five feet taller, especially when a sound wall will rise another 4 to 8 feet above rail level, makes a huge difference to visual impact.

  • PAMPA sandwich: The finalized application for the next federal funding increment includes a description of the project phasing plan for the peninsula. Phase 1: 4 tracks Redwood City and north + PTC. Phase 2: 4 tracks Mountain View and south + electrification. That leaves Palo Alto - Menlo Park - Atherton (PAMPA) with a two-track at-grade gap, left until such a time as there develops overwhelming pressure to fill it in.

  • VTA buried: The light rail spur in Mountain View is buried under the Stevens Creek, to make room for the expansion of the corridor. That doesn't strike one as the cheapest way to do things.

  • Viaduct vengeance: A FIVE MILE, 60-foot tall viaduct is planned in Santa Clara, an area of the corridor that is (a) already fully grade separated and (b) mostly wider than 100 feet. These people don't do subtle: their vocabulary is reinforced concrete, shoring walls and outrigger bents. This area of primarily commercial and industrial properties is less likely to oppose such a gratuitous structure. Operationally, the HSR viaduct needlessly prevents Caltrain overtakes anywhere between the Santa Clara and Lawrence stations. All pain, no gain... or from their point of view, all profit.
Clearly, there is a long way to go before context-sensitivity is achieved.

04 August 2010

Elevated Blight in San Mateo

The elevated structure spans across several blocks of San Mateo, like a gash through the heart of downtown. Its 67-foot width casts vast shadows onto downtown shoppers, like a freeway overpass, although women and children seem to pass underneath without being attacked. The concrete structure, strangely free of graffiti, provides a full 16 feet of free clearance underneath it for trucks. Three stories up above, the side walls of the elevated bridges loom a full 25 feet over the street. To add insult to this injury, metallic poles tower another 18 feet above the structure, bringing its overall height to an incredible 43 feet!

If you know San Mateo, you might have guessed this describes the Central Parking Garage, a structure with presence, visual impact, and context-sensitivity resembling the elevated, four-track high-speed rail corridor that residents fear.

02 August 2010

Peninsula (Northeast) Corridor

It's official: as noted on page 7 of the latest program management team monthly progress report, the selected track arrangement for the peninsula corridor, a key architectural decision with extensive ramifications for Caltrain operations, is slow-fast-fast-slow (SFFS). That means the express tracks will be located in the middle of the right of way, with Caltrain local tracks flanking them on each side. This arrangement is similar to the Northeast Corridor throughout New Jersey (photo at right by theahnman). From the report:
While the June schedule does not show any change in the deliverables dates, in July there will be a change in the delivery of the 15% integration package from September 2010 to October 2010 to change the alignment of the Caltrain tracks to the outside and HST tracks to the inside tracks to reduce the footprint at Caltrain station locations (using side rather than center platforms).
The good news is that the previously-favored, segregated SSFF or FFSS arrangements seem to be off the table. Those arrangements would have prevented the express overtakes that are the key to an effective Caltrain timetable, and would have forced wrong-way movements whenever any one of four tracks went out of service. Wrong-way movements vastly diminish track capacity and exacerbate cascading delays, where one late train makes a mess of the whole timetable--as any regular Caltrain rider knows all too well. So that's the good news.

The bad news is that Caltrain will be stuck with side platforms. When a Caltrain track goes out of service, as it inevitably will, routing trains to the opposite platform will now require cutting across the HSR tracks, as shown in the diagram at left. No more central island platforms, which have undeniable operational advantages as well as simplified passenger access.

Given the choice between giving up island platforms (SFFS) or giving up overtakes (FFSS / SSFF), then SFFS wins by a mile because overtakes are key--but that's really a false choice, constrained by the menu of alternatives. The one alternative that is seemingly not being given due diligence is FSSF.

Their logic might go like this:
  1. Caltrain design criteria (Chapter 3, paragraph 1.1.d) and HSR Technical Memo 2.2.4 (Station Platform Geometric Design, section 6.1.3) dictate that platforms must be perfectly straight.

  2. Straight island platforms require a double-reverse curve "wow" around the platform at every station, conflicting with HSR Technical Memo 2.1.2 (Alignment Design Standards for High-Speed Train Operation, section 6.1) that prohibits more than four so-called direction changes per mile.

  3. The reverse curve "wow" beyond each end of the island platform consumes an inordinate amount of land precisely where it is most valuable, in the denser suburban cores where train stations tend to be located.
That's a perfectly logical chain of reasoning, but it is unfortunately based on a poorly conceived requirement that prohibits curved platforms.

As discussed in Football Island, curved platforms allow the "wow" around the center island platform to be much more compact, using barely any more land than the side platform configuration. The diagram at right (do you see the football?) highlights the difference in green, amounting to about a half acre. With the exceedingly generous clearances likely to be used--the diagram shows a mere 75 feet of right of way width!--the difference would be even less. Now imagine a straight island platform, not shown in the diagram, where the green area would need to bulge out over a far greater length; the extra area would amount to the entire area of the platform, 30 x 750 feet or another half acre. That is indeed a waste of valuable land.

Fast-Slow-Slow-Fast isn't some far-fetched concept. It works in Sweden, and it would work here, far more efficiently and flexibly than a carbon copy of the Northeast Corridor. Why not give a careful second thought to curved platforms, unencumbered by rote compliance with ill-considered specification requirements?

31 July 2010

If We Had Four Billion Dollars...

The recent Executive / Administrative Committee meeting featured an interesting memo regarding the application for another $2.3 billion of HSR federal funding to be distributed nationwide. Last time around, the CHSRA bagged $1.85 billion out of $8 billion of ARRA stimulus funding distributed nationwide. The additional funding, if CHSRA continues to bat .231, is on the order of $530 million.

The memo examines various scenarios where ARRA funding and Prop 1A bonds, of which a total of $3.3 billion is claimed to be available, are combined with new federal funding to reach a threshold of "independent utility" for one of the many segments of the California high-speed rail project.

If the San Francisco to San Jose segment were chosen as the initial recipient of this funding, then nearly $4 billion would become available for construction, still quite short of what will ultimately be necessary. The hypothetical question examined in the memo is how this money would be spent.

Salient points:
  • the CHSRA is starting to realize that they can't use a "Big Bang" approach where everything is constructed at once. For the first time, there is talk of phasing and a "building block" approach within the peninsula segment.
  • phasing means construction would start first on the ~26 mile stretch between San Francisco and Redwood City, avoiding the controversy in PAMPA (Palo Alto - Menlo Park - Atherton).
  • $4 billion would only cover elevated grade separations; trenches through Burlingame and San Mateo would not be included.
  • ERTMS is mentioned in the same breath as CBOSS, an encouraging first baby step in the right direction.
  • FRA would likely frown on using high-speed rail funds to provide "independent utility" for what is primarily a commuter rail corridor, not an intercity corridor
Of course, all this is purely hypothetical. Consider that (1) only one single segment could be started as the marquee project for California high-speed rail; (2) the high level of controversy on the peninsula makes it highly unlikely that the environmental clearance will be obtained on schedule; and (3) short-term improvements that benefit primarily Caltrain will be difficult to pass off as "independent utility" for intercity rail service. The likelihood of $4 billion suddenly hitting the peninsula is fairly close to zero.

27 July 2010

Odd Stacking

The odd stacked alternatives shown in the figure at right (ripped out of a recent technical working group presentation) make little sense, for a number of reasons that were previously discussed.

Recall that track stacking, besides entailing very intensive and profitable construction of complicated earthquake-resistant civil structures on the taxpayer's dime, is intended to reduce the right-of-way width required to build a four track corridor, presumably to appease neighbors and minimize residential property takes. A brief glance at the above drawing (which should also reinforce fears of a separate-but-equal approach that is disastrous for Caltrain) necessarily leads to ONE of the following two conclusions:
  1. The planners have lost sight of what they were trying to achieve, in effect destroying our village in order to save it. The stacked solution on the left requires "only" 87 feet of ROW width, while the one on the right requires 119 feet of ROW to make room for a Caltrain platform down in the trench. These elephantine structures, making use of enormous amounts of concrete, seem to miss the whole point of stacking: to save space. If you were to nibble back just 4 feet out of the 13 feet (thirteen!) devoted to drainage and third-party utility easements, you could simply stick all four tracks down in that trench on 15-foot centers. Dear peninsula communities: do you prefer 13 feet for drainage and utilities, and oh, by the way, a viaduct that looms 30 feet above ground level (16 feet of road vehicle clearance, 10 feet of viaduct box + rails, and 4 feet of sound wall) with another 30 feet of overhead wires towering above that? Or would you rather we cut back to 9 feet for drainage and utilities, and the viaduct disappears entirely? Let's think it over, for about a microsecond.

  2. The planners are not so subtly trying to sand-bag the stacked options to gain community buy-in for property takes. Making the stacked alternative look this bad on paper fulfills the dual goal of giving it environmental due diligence under CEQA and ensuring that public opinion will be "stacked" against it, setting it up for being "not carried forward" in a way that is impervious to future litigation. These are the lengths to which we must go to take 5 feet of somebody's back yard.
Since one would prefer to assume that planners are not stupid, and that they don't take peninsula residents for idiots, #2 seems more likely. Stay tuned for the answer: the supplementary alternatives analysis report for the peninsula high-speed rail project is scheduled to be revealed to the public on Thursday, August 5th in San Francisco.

23 July 2010

Metrics That Matter

The future of Caltrain (if it doesn't go bankrupt first) is likely to hinge on the quality of the service provided. Even if they don't ride the train, all peninsula residents can still benefit from quality train service that vacuums traffic off the road. So how exactly does one define and measure Quality?

From the point of view of a Caltrain rider, quality can be defined in terms of just four Metrics That Matter.
  1. What is the average trip time between my origin and my destination?
  2. What is the best trip time between my origin and my destination?
  3. At my origin, how long is the average waiting time between trains that go to my destination?
  4. At my origin, what is the longest waiting time between trains that go to my destination?
The first two metrics measure trip time on board the train, and the next two can be used to measure waiting time on the platform, which is just as important, and often perceived as longer than it really is. Notice that all four metrics are measured in units of time, between a specific origin and destination. These metrics don't measure operating cost. Not ease of maintenance. Not reduced emissions or noise. Not electricity or diesel. Not seats per hour. Not consist utilization. All those other metrics are important to a train operator, but riders don't understand them, and frankly don't care. Riders care primarily about time.

Figuring the Metrics

The four metrics that matter are objective measures that are reasonably straightforward to extract from a timetable. A computer can churn through a timetable to extract the metrics for every possible origin & destination pair, by making a few simple assumptions about rider behaviors as shown in the graphic at left.

For example, we can crunch the current Caltrain timetable (with 90 trains per weekday and 5 trains per peak hour), with the result shown at right. For simplicity, the graphic shows a limited sample of ten stations; simply follow the blue lines to find the intersection of the desired origin and destination, and read off the four metrics. A more complete version of this table is provided below.

Effective Trip Time

The four metrics are useful to consider separately, but ultimately we'd like to compare entire timetables to determine which timetable is better. To do this, we need to consolidate the four metrics that matter into a single "effective trip time" metric for each origin and destination pair. Thus far, the four metrics required very few assumptions and could be quantified quite objectively. As we construct an effective trip time metric, things get a bit more subjective and debatable.

The effective trip time is not the trip time experienced by any particular passenger; rather, it is a single figure of merit that reflects a global average of trip times taken by all passengers between a given origin and destination.

If a passenger showed up randomly, the effective trip time would simply be the average trip time plus 50% of the average wait time. However, most passengers don't show up randomly. They tend to show up before their train, and they also tend to prefer faster express trips. Therefore, we can create a reasonable measure of effective trip time as the sum of:
  • 70% of the average trip time
  • 30% of the best trip time (to favor express service)
  • 20% of the mean wait between trains (far less than the random arrival figure of 50%)
  • 15% of the maximum service gap (to penalize very large gaps between trains)
The first two terms of this sum (70% + 30%) bias the on-board portion of the trip toward express service. The last two (adding up to 35% of headway if the timetable is regularly spaced) reflect the time waiting at the station, with most but not all passengers showing up some minutes before their train. The combination of the four metrics that matter into a single effective trip time allows us to represent the current Caltrain timetable as shown in the graphic at right.

Notice that the effective trip time metric is constructed so as to punish very large service gaps. Due to the speed / frequency trade-off that Caltrain currently must contend with, many smaller stops are severely under-served during rush hour, commonly with gaps of 40 minutes or more, to clear the tracks for Baby Bullets. This is reflected in the table: for example, Palo Alto to 4th & King (the highest traffic and best-served O&D pair) is covered in 47 minutes, but the similar distance between California Ave and 22nd Street (an under-served O&D pair) effectively takes 67 minutes.

Whether or not you agree with the exact weighting used to construct the effective trip time metric, the fact remains that with some optimally chosen weights, the metric is a valid one. The numbers can easily be recalculated using different weighting assumptions.

Measuring the Quality of an Entire Timetable

Now that we have a single number that describes the effective trip time between any given O&D pair, it's time to generalize the approach to encompass all O&D pairs and to construct a single figure of merit that captures the service performance of an entire timetable. Obviously, not all O&D pairs can be served optimally: any timetable is inherently a trade-off between minimizing trip times for most riders at the cost of longer trip times for some riders. Figuring out what works best thus requires ridership weighting.

Ridership weights can be derived from actual weekday ridership data, shown as blue bars in the chart at right (these weights have been scaled such that they add up to one). Unfortunately, actual ridership is not always an exact reflection of underlying travel demand. Some stations suffer from a vicious circle; they have poor ridership in large part because they are poorly served. A good example of such a station is California Avenue in Palo Alto, where average weekday ridership was 1225 riders in 2002 before service was cut to make way for the Baby Bullet, dropping to 891 riders in 2010. This 27% drop occurred at the same time as overall ridership increased by 19%, and is unlikely to have been caused by any shifts in employment or residential patterns in the rather thriving vicinity of this station.

The most desirable approach would be to implement a full-featured ridership model, of the sort that has recently generated so much controversy for the state-wide high-speed rail project. That is unfortunately beyond our means, so we will simply use direct ridership weighting, with some filling in where service currently isn't provided (e.g. Transbay or Atherton).

The ridership weight of an O&D pair is the product of origin ridership and destination ridership (a measure of how many people travel on that O&D pair) and is shown by the light blue circles in the figure at left. Big circles mean heavy ridership, small circles mean light ridership. An optimal timetable will seek to provide the best effective trip time for O&D pairs where a big circle represents heavy ridership.

To construct a single figure of merit for an entire timetable, we first need to come up with a new, ridership-weighted service score for each O&D pair. This score, where higher is better, is the product of origin and destination ridership (the size of the blue circle), divided by effective trip time. Dividing by effective trip time means that shorter trip times increase the score for that O&D pair. Now all that's left to do is to sum up all the O&D service scores, and presto, we've got ourselves a single figure of merit. This allows us to compare timetables and, provided that we agree on the method used to construct that figure of merit, to determine objectively which of two timetables is the better one.

Any disagreements about which is the best timetable can then be reduced to disagreements over the scoring method. Planners tend to fall in love with their favorite solution, so taking the discussion away from the solution and focusing instead on the scoring method allows a dispassionate debate that is less colored by subjective preferences. Indeed, without an agreed-upon scoring framework (clearly defined metrics), comparing timetables is a subjective and useless exercise.

The Great Timetable Shoot-Out

Enough with metrics, are we ready for some fun, or rather, as much fun as can be had with timetables? Let's put three different timetables through their paces, and see how they stack up in terms of service quality.

Contestant #1: today's 90-train-per-day, 5-train-per-hour Caltrain timetable, to which we will assign a score of 100 for the purpose of comparison.
Contestant #2: the official Caltrain 2025 timetable published in Appendix K of the Preliminary Alternatives Analysis. This 162-train-per-day timetable shows 10 trains per hour in each direction at peak times, with every train performing a skip-stop pattern to keep the entire end-to-end run under 65 minutes--about ten minutes slower than today's Baby Bullet.
Contestant #3: a plain vanilla takt-timetable featuring only 6 trains per hour in each direction at peak times. Four of those trains are all-stops locals (running at regular 15-minute intervals, with a 93-minute run from Transbay to Tamien) and two of them are expresses, which take advantage of the four-track peninsula rail corridor to overtake locals. One of those overtakes occurs at the middle of the line at the Redwood City station, where the local and the express stop simultaneously on opposite sides of the same platform and exchange passengers--at this stop only, we make an exception to the 3-minute transfer rule. This cross-platform transfer extends the benefits of express service to a much wider selection of O&D pairs than today's Baby Bullet.
While Contestant #2 takes first place, Contestant #3 is competing with a huge handicap of 40% fewer trains per hour, but comes in just 1% behind in service quality. That's right: there exists a SIX train per hour time table that provides nearly the same quality of service as Caltrain's TEN train per hour timetable. How can that possibly be?

The secret weapon: the mid-line overtake.

The Trickle Down Effect

With the peninsula being reconfigured to four tracks for high-speed rail, it would be a terrible shame not to take advantage of some of that new track capacity to run better and more efficient local service, providing measurable benefits to local peninsula communities. Better service just might be the sugar coating to make the bitter pill of high-speed rail go down a little bit easier in places like Palo Alto, Atherton, Belmont, or Burlingame. Otherwise, why even bother?