31 August 2022

HSR Lays an Egg in Caltrain's Nest

California's high-speed rail project has finally reached a milestone 14 years after the passage of Proposition A in 2008 with the board's certification of the Final Environmental Impact Report for the San Francisco - San Jose project section.

This voluminous document has come a long way since the early days of a four-track 125 mph rail corridor initially envisioned for our region, having been whittled down to a two-track 110 mph "blended system" project that shares tracks with Caltrain without building any new overtaking tracks. Nevertheless, the cost estimates for the project have ballooned to $5.3 billion.

How do you add four high-speed trains per hour per direction, traveling at peak times between San Francisco and San Jose in just 48 minutes (by the way, 18 minutes slower than promised in the HSR bond measure) while building no new tracks and without disrupting Caltrain service? The answer is, you can't.

Instead, the high-speed rail project plans to take over the peninsula rail corridor and become a parasite to Caltrain. Here's how.

The FEIR's Volume 2 Appendix 2-C Operations and Service Summary contains what is described as an "Illustrative Timetable" of this blended service featuring 6 Caltrain + 4 HSR per hour per direction. The assumptions for this timetable include:

  • Caltrain is operated as a skip-stop service with 3 different stopping patterns.
  • Caltrain EMUs operate at up to 110 mph, their design top speed.
  • Caltrain station dwells are 30 seconds, consistent with system-wide level boarding.
  • Caltrain operates in salvos of three closely-spaced trains every half hour, leaving large gaps for high-speed trains to travel without being delayed by Caltrain. This bunching is flatly denied on page 3.2-91 of the FEIR, inconsistent with the Illustrative Timetable.
  • Two out of three Caltrains are held for about 5 minutes at either Bayshore or Lawrence station to allow high-speed trains to overtake them.

Additionally, we can make the reasonable assumption that peninsula commuters will be priced out of high-speed rail service, meaning that HSR will not provide many trips with origin and destination between San Francisco and San Jose. Every local peninsula trip taken on a high-speed train potentially displaces a longer statewide trip with much higher fare revenue for the operator, especially at peak times. In a yield-managed fare structure, local HSR trips will therefore be priced punitively. This isn't just speculation, it's well-established practice: Amtrak's premium Acela Express can technically be used to commute from Stamford, Connecticut into New York City, but it can easily cost you over $100 per trip, compared to the $15 peak fare on Metro North. In much the same way, every local SF-SJ passenger would potentially displace a more lucrative SF-LA passenger. Punitive local ticket prices will mean zero local ridership, so we shouldn't figure any HSR services into the scoring of service quality.

Let's put this in our handy taktulator and figure a score for this timetable. Remember, Caltrain's 2011 timetable is the baseline with a score of 100.

HSR FEIR Caltrain, no DTX: Score = 135 service points -- compare that to 147 service points with regularly-spaced 8 train per hour service, as planned in Caltrain's service vision and enabled by a new overtaking station in Redwood City.

HSR FEIR Caltrain, with DTX: Score = 235 service points -- compare to 250 service points with regularly-spaced 8 train per hour service as planned by Caltrain.

In both cases, the HSR timetable improves over the 2011 timetable (score = 100) by only 75 - 90% as much as the planned Caltrain timetable. Despite the higher train speeds, the bunched-up and irregular skip-stop service pattern with long overtaking dwells makes numerous Caltrain trips less convenient. On the plus side, this blended service can be operated with a fleet of 6 fewer trains than Caltrain's more frequent 8 tph service pattern. On the minus side, those trains will be more crowded. Note our taktulator tool measures service quality only from the standpoint of one typical user (weighted by origin and destination population and jobs density), without quantifying overall ridership demand or the resulting level of crowding.

Confronted by numerous stakeholders with the seeming contradiction between Caltrain's plans and its own blended service planning, the HSR authority offers Standard Response FJ-Response-GEN-4: Consideration of 2040 CaltrainService Vision and Caltrain Business Plan, with key points summarized below:

  • Caltrain's Service Vision is aspirational and isn't an approved or funded project.
  • The Service Vision is insufficiently defined to be analyzed in the EIR and is not "reasonably foreseeable" under CEQA.
  • The impact on Caltrain service wouldn't rise up to the level of a "significant impact" anyway.
  • The illustrative timetable is only used as a reasonable basis for analysis and there may exist better timetables.
  • It will be Caltrain's job to environmentally clear (and fund) future improvements associated with the Service Vision, such as additional passing tracks to support HSR service in the corridor.

In the HSR project's view, Caltrain will be fully on the hook for upgrading its own facilities to continue hosting HSR even as it becomes more difficult to do so. This sets up unhealthy incentives where capital projects that actually improve Caltrain service, and might create inconvenient "facts on the ground" for HSR, are quite likely to be delayed and de-funded to ensure the corridor stays clear for the future hatching of the giant egg that HSR just laid with this EIR.

31 May 2022

Capital Spending for Better Service

Wouldn't it be great if you could quantify the service benefit of capital improvements, to compare and prioritize them by how much better train service results?  We can, and using our handy Taktulator, we will. This service pattern evaluation tool was formulated around time-based service quality metrics. We use it to explore future improvements to the peninsula rail corridor.

Today's 2022 Timetable: 94 service points -- The current peak schedule with four diesel trains per hour features very generous padding and SF - SJ trip times ranging from 66 minutes (express) to 99 minutes (local). The less-than-100 score indicates that service quality has dropped since 2011 when there were five trains per peak hour. The Taktulator score is calibrated such that the 2011 Caltrain timetable scores exactly 100 points.

Caltrain's 2040 service vision foresees eight trains per peak hour per direction (not counting HSR). Let's start with a service frequency of 8 trains per hour-- except for the sake of exploring and quantifying the value of capital improvements, we'll start from a hypothetical case that will never happen: eight trains per hour of today's diesel service, making all local stops.

Hypothetical diesel all-stops local, 8 tph: Score = 109 service points (+16%) -- The doubling of hourly frequency improves the service score by 16%, despite each train being slower. The extra time riding an all-stops trains is more than offset by the much shorter wait time at the station. For example, maximum wait times in Belmont plummet from one hour to just 7.5 minutes. Unfortunately, this service pattern would take an unrealistic 32 trains to operate, because each train takes 94 minutes to go between SF and SJ. The hypothetical scenario still illustrates the magnitude of the effect of doubling frequency.

Add electrification: Score = 121 service points (+11%) -- Electrification is worth another +12 points relative to diesel, thanks to the shorter trip times that come from the higher acceleration capability of EMUs. Those savings accrue to a full ten minutes between SF and SJ for an all-stops local. Station dwell times are still booked at 45 seconds, a longer duration that reflects the lack of level boarding. Thanks to the faster trip times, the fleet requirement has dropped from 32 trains to 28 trains. Service speed saves money, not just on fleet size but also by increasing the hourly productivity of train crews (in terms of passenger-miles served).

Add Redwood City hub station: Score = 131 service points (+8%) -- If trains cannot pass each other, there is no room in such a frequent timetable for express service. A new four-track station at Redwood City, where express trains can overtake locals on opposite sides of the same station platform (so that passengers may transfer seamlessly between local and express) gives the best of both worlds: frequent service AND express service. For now, we'll assume this station has only two-track approaches, requiring trains to arrive and depart serially. In practice, this means every local must wait more than 5 minutes or the equivalent of two signal headways to let the express catch up before RWC and then pull ahead after RWC. The stopping patterns start to look like Caltrain's 2040 service vision.

Add Redwood City quadruple approach tracks: Score = 138 service points (+5%) -- If quadruple tracks are added approaching Redwood City from the north and south, then local and express trains can make parallel moves into and out of the hub station, removing the requirement for every local to wait there for five wasteful minutes. To unlock this benefit, the quadruple track overtake section needs to extend to one station on either side of RWC, so every local train can make productive use of those five minutes. In the Taktulator, we simulate this by having every local train stop at San Carlos and Atherton, which (despite its closure) stands in for a new Fair Oaks infill station at 5th Avenue. This suggests a hub station is about 1.7x more effective if it forms the center of a three-station quadruple track section. Having fully half your trains save five minutes is a huge service improvement!

Add level boarding: Score = 147 service points (+7%) -- Where electrification saved time in motion, level boarding saves time at rest by shaving 15 seconds of dwell time at each station, as step-free access smooths passenger boarding and alighting. Level boarding gives not only short dwell times but predictable dwell times (for example, wheelchairs don't take longer to board) so we can also tighten up the padding margin in the timetable, cut in this example from 12% to 7%. Interestingly, the end-to-end corridor times fall below a threshold that allows turning a train sooner, reducing fleet requirement from 28 to 24 trains. This isn't necessarily an effect of level boarding itself, and only illustrates that a series of small improvements can result in a discontinuous benefit when a certain threshold is reached.

Add SF Downtown Extension: Score = 250 service points (+70%) -- There are more jobs (over 100,000) located within a half mile of the Transbay Transit Center than there are jobs within a half mile of every other Caltrain station combined. This makes downtown SF a dominant node if added to the system, a fact that is reflected in our census-based weighting of available trips. No other improvement comes close.

Here is how these service improvements stack up against each other, plotted as the logarithm of the ratio of after/before scores, which gives you their relative impact. They can be constructed in a different order than imagined above, but the relative proportion of each improvement should remain approximately similar:

Bar graph of the relative service quality improvement of Caltrain capital projects

Here are some key takeaways:

  1. Grade separation projects do not improve train service. Exceedingly rarely, they do prevent a train delay, something that is not captured in this analysis. On the basis of the time metrics of a typical trip, however, the service improvement of grade separations is ZERO. This should factor strongly into how many billions we are collectively willing to spend on them relative to the other capital improvements discussed here.
  2. The benefits of electrification alone (without other improvements) are mediocre at best. On the basis of our time metrics, service quality is only improved by about 11% relative to an equivalent diesel scenario. Caltrain can't just finish the electrification project and call it good enough.
  3. The Redwood City hub station now in the planning stages is surprisingly beneficial to service quality. While packaged and sold as a grade separation with a bonus of expanding the train station, it is hard to overstate the service quality benefit of the new hub station. Even as planned by Caltrain (with two-track approaches from the north and south) the new station produces nearly as much service improvement as the entire electrification project.
  4. The Redwood City hub station as planned by Caltrain with two-track approaches is operationally ineffective. It can be juiced up to 1.7x more benefit to service quality by making it the center of a four-track overtake facility spanning just three stations: San Carlos, Redwood City and a new Fair Oaks infill station at 5th Ave. The southern portion of this four-track facility already exists today. Together with 4-track approaches, the Redwood City hub improves service quality by a greater proportion than the entire electrification project! That's why it is critical that planning for the Redwood City grade separations allow for four tracks throughout.
  5. Level boarding provides over half the service quality improvement of electrification, and is likely to be a much cheaper capital investment. However, it makes sense to do it after the hub station.
  6. The downtown extension in San Francisco will be a game changer for service quality. The transportation industrial complex knows this and will make us pay dearly for the DTX project. However, the additional billions for the PAX (Pennsylvania Avenue Extension, a city-desired grade separation) add absolutely nothing to service quality, and should never be allowed to be bundled with the DTX project. Every capital dollar should improve service quality.
  7. The Redwood City hub station (with four tracks, not two!) is worth one fourth of the service benefit of the DTX. That means we should (a) not be shy about spending capital dollars to build it and (b) stop selling it as a grade separation, because that isn't the story here-- it should be about a new infill station, seamless transfers, and better service quality system-wide.

As always, the analysis provided here can be quibbled with and improved upon, and you are encouraged to "do your own research" by trying out your own service patterns in the Taktulator.

13 March 2022

News Roundup, March 2022

It's been a while since the last post, but fear not this blog is still alive.

Caltrain's First Major Accident: on Thursday 10 March 2022, a southbound train was unable to stop before ramming into at least two rail-going flatbed crane trucks being used by an electrification construction crew. 13 people were injured with five requiring hospital treatment; thankfully there was no loss of life. With the new positive train control (PTC) system in place, this collision should never have happened. The fact that it did has drawn scrutiny from the National Transportation Safety Board, which dispatched an investigation team to the site of the accident in San Bruno. The causes of such accidents are often multiple, subtle, and complex, and it will take more than a year to assemble the evidence, identify root causes, and draw out lessons learned. NTSB staff reported some preliminary points at a press conference on March 11th:

  • The impact occurred at approximately 60 mph and the train came to a stop over a distance of over 500 feet.
  • The PTC system is designed to prevent train incursions into established work zones.
  • The PTC system was on and active on the accident train.

While we should be wary of speculation, it is possible to discuss additional relevant points:

  • Train 506 was due to depart Millbrae at 10:34 AM. If as stated the accident occurred just before 10:40 AM, then the train was several minutes behind schedule.
  • The head end of the train stopped at milepost 11.9, so impact occurred at about milepost 11.8.
  • Milepost 11.8 is adjacent to a staging area on the west side of the tracks that is used by the electrification contractor.
  • The location is less than a mile south of San Bruno curve, one of the sharpest curves on the entire peninsula rail corridor. The train would have traversed this curve no faster than the PTC-enforced maximum speed of 65 mph before accelerating again towards 79 mph after the curve.
  • The humped vertical profile of the San Bruno grade separation would have obstructed the train crew's view of the work crew's trucks until about milepost 11.1, at San Bruno Avenue.
  • At an average of 65 mph, the 0.7 miles from the point of initial visibility to the point of impact would have gone by in just under 40 seconds.
  • The 1.25% downhill grade towards the impact point would not have helped the train's emergency braking performance.

Unanswered questions include why were the construction vehicles and the train on the same track, why did the PTC system not prevent the collision, and whether there have ever been other near misses over the past several years of electrification construction. The NTSB report will tell.

May everyone hurt by this accident make a full recovery.

More Electrification Delays: while pole foundations are done, everything else is behind and slipping even from the new delayed schedule. The monthly reports for the project have been significantly abbreviated. The long pole in the tent is the grade crossing warning system, and it just so happens that the new program manager at Caltrain previously managed Denver's electrification project and has direct and personal experience with overcoming the great Denver grade crossing fiasco. From the December report to January, overhead contact system completion has slipped by 4 months. Oddly, after years of study and paying a nine-figure amount to PG&E for substation upgrades, the project is still embroiled in back-and-forth with the utility over how the large single-phase loads of accelerating and braking electric trains might throw the electric grid out of balance. One thing is clear, PG&E knows just how hard to squeeze Caltrain.

Electric Train Modifications: feature by feature, the EMUs are being downgraded to act like an old Bombardier bilevel train. The first EMU trainsets, numbers 3 and 4, are due in California sometime in April March 19th. They will sport two noteworthy changes not seen in any official photos or renderings. The upper set of doors have been sealed off (likely permanently) with window plug panels, and the automatic couplers have been downgraded to old-school AAR knuckle couplers.

Governance Politics: the three-county custody fight over Caltrain rages unabated, sucking all the oxygen away from critical planning for what comes after electrification. Momentum for the business plan effort seems to have stalled entirely. The two key upgrades yet to come are level boarding and a four-track elevated grade separation throughout downtown Redwood City, neither of which are being sufficiently attended to while the board's attention is fixated on questions of power and influence.

CBOSS Dumpster Fire Update: speaking of fires and PTC, the CBOSS case is still making its way through San Mateo County Superior Court (under case file 17CIV00786). Last year, Caltrain and Parsons (the CBOSS prime contractor) agreed to stop fighting each other and ganged up against Alstom (formerly GE Transportation Systems), the supplier of the flawed CBOSS software. Ten years after contract award, six years after breach of contract, and five years after lawsuits started flying, the case is coming close enough to trial that the parties have each prepared a trial brief that very nicely summarizes the making of this fiasco from their respective viewpoints. Here are hot-off-the-press direct links to the Caltrain & Parsons Trial Brief and the Alstom Trail Brief.

Update 3/19 - Board Workshop on Caltrain Finances: the slide deck for the upcoming board workshop to discuss what to do about the railroad's new fiscal reality (high fixed costs and only ~1/3 of the usual farebox revenue) is now posted. What is most remarkable is what is not in the slides, which are basically a giant shrug ¯\_(ツ)_/¯ in the face of the deficit forecasts shown in slide 46. If this is truly an existential fiscal emergency, one wonders why the cost of assistant conductors is not on the budget negotiating table. In 2019, the cost of assistant conductors was $7 million/year, and has since grown proportionally with more train service and annual pay raises, likely to about $8.5 million/year for 2022. With a further service increase to 116 trains/day when electrification begins, the cost of assistant conductors will exceed $10 million/year in 2025. While Caltrain is vulnerable to its labor unions and reluctant to raise such a sensitive matter, the time has come for the second conductor to follow the fate of other redundant and obsolete train crew positions such as fireman and brakeman.

Battery EMUs: from the "are you insane?" department comes a minor bullet point on slide 59 of the same packet, where an area of focus for FY23 is to "Advance sustainability through completion of PCEP and further exploration of potential for battery EMUs." Please don't. The whole point of PCEP and EMUs is to not be seduced by world-unique technical solutions and to not haul around many tons of battery dead weight. The only area that needs focus is to further explore the provenance of this shockingly idiotic idea.

19 September 2021

Down the Tubes with DTX!

DTX overview
San Francisco's Downtown Rail Extension project (DTX), officially known as the Transbay Transit Center Program Phase 2, is a two-mile tunneling project to extend the peninsula rail corridor from its existing terminus in the Mission Bay neighborhood to the purpose-built basement "train box" of the Salesforce Transit Center (SFC). The project is regionally important, as there are more jobs located within a half-mile radius of the SFC than within a half-mile radius of all Caltrain stops combined, from 4th and King all the way to Gilroy. The DTX is nearly shovel-ready, in the sense that environmental clearance is in hand and engineering is being advanced to award construction contracts the moment a key ingredient becomes available: money. Gobs and gobs of money.

Too Big To Fail

The last time the costs of the Phase 2 project were tallied in 2016, the total came to $3.9 billion in year-of-expenditure dollars assuming a 2025 opening. Due to delays, we can anticipate at least another five years of escalation at 5%, bringing us to $5 billion before any changes to the project scope. One can reasonably expect that Bay Area transit agencies' proven inability to deliver mega-projects on budget or on time is quite likely to blow up costs well beyond these figures. As a recent example, the Phase 1 project, completed in 2019, cost $2.4 billion (year-of-expenditure) or about 50% more than the $1.6 billion YOE budget of May 2010, adopted after the train box scope was added.

The DTX project's regional, state and national significance is certainly not lost on our Transportation Industrial Complex. To improve the chances of getting the Phase 2 project federally funded (after which any cost growth becomes easier to fund, following former SF mayor Willie Brown's "theory of holes"), the TJPA is undertaking a phasing study to make the project appear more thrifty. The various approaches include deferring or deleting components of the project, such as a pedestrian connector to BART, an intercity bus facility, and an extension of the basement train box. This nibbling around the edges amounts to $0.4 billion in 2027 dollars or about 8% of the total Phase 2 project cost, a drop in the bucket.

A $30 million project development study is now in the pipeline to get Phase 2 to the state of readiness required to apply for federal New Starts funding by August 2023.

PAX: The World's Most Expensive Grade Separation

If you thought the cost of grade separations is exploding, you really haven't seen anything yet: meet the Pennsylvania Avenue Extension (PAX) addendum to the DTX, a grade separation project that will approach $2 billion for two crossings, reaching the stratospheric cost of $1 billion per crossing.

Even after spending $5 billion (before inevitable cost overruns), the DTX project will leave two existing street crossings at grade, at Mission Bay Drive and 16th Street. Not to be outdone, the city and county of San Francisco has performed a methodical series of planning studies to conclude that a new grade separation project is needed. Rather than taking on the challenge of bending some design rules to keep it simple and make it fit, the favored paint-by-numbers engineering solution is a bored tunnel, which averts any conflict with a planned 27-foot sewer pipe and the sacrosanct pile foundations of the I-280 viaduct, each of which are under the jurisdiction of other agencies. The combined cost of DTX + PAX is estimated at $6.0 billion. Take away the latest (2016) $3.9 billion cost estimate of DTX and you get about $2 billion added for PAX.

Link21 Crashes the Party

Meanwhile, BART is in the early planning stages for beefing up its throughput capacity between the greater East Bay and San Francisco, with a second Transbay Tube. It's worth pausing for a moment to consider what an astonishing piece of infrastructure the first Transbay Tube already is: it carries almost twice as many people during rush hour as the entire ten-lane freeway that is the San Francisco - Oakland Bay Bridge, and at significantly faster speeds. Looking past the pandemic, long-term growth trends indicate that the region must plan for a second Transbay Tube.

Transbay Tube II is the centerpiece of an enormous regional rail program known as Link21, the scale and ambition of which dwarf the DTX. While there are many decisions yet to be made about the implementation details of Link21, perhaps the most critical decision centers on what technology to put in the tube: wide-gauge BART, standard-gauge regional rail, or both.

This question is already of great concern to TJPA, which writes in its August 20, 2021 Phasing Study:

BART and Capitol Corridor’s Link21 program is currently in the early stages of development and has not yet determined a preferred alignment, technology, or rail gauge options to meet their goals and objectives for a future transbay rail crossing. As expected at this stage of development, all options remain available for consideration. For example, Link21 may determine that a second transbay crossing best meets stakeholder needs if it provides additional capacity for the BART network only and does not provide a standard gauge rail crossing of the Bay. BART’s infrastructure and trainset design, however, are incompatible with Caltrain and CHSRA standards. Most significantly, BART operates on a wider track gauge with vehicles that may not meet collision requirements, and therefore a BART-only connection would not relieve congestion and conflicts on the DTX.

We can already see a problematic mindset emerging here, where "BART" is automatically conflated with "five-foot-six track gauge," setting up a false dichotomy of BART-or-standard-gauge.

Caltrain + BART: a Necessary Merger

The false dichotomy of BART-or-standard-gauge threatens to poison the debate around Link21 alternatives. The Transportation Industrial Complex has a vested interest in this incompatibility, as it ultimately forces multiple mega-projects to be built. Why build it right when you can build it twice and get paid twice? From the standpoint of scope and profit maximization, it would then make sense to keep DTX and Link21 as separate projects, despite their overlapping purpose and need to link the greater Bay Area megaregion together using high-capacity passenger rail infrastructure. Seamless integration is good for riders and taxpayers, but not so great for consultants and civil engineering mega-firms. That's why these firms have an interest in propagating the myth that BART and standard gauge rail will always be mutually exclusive.

Removing this false dichotomy is becoming a primary reason for merging Caltrain with BART to form a single Bay Area Rapid Transit system, although there are many other reasons. BART does not have to be synonymous with wide gauge; indeed, BART already operates a seamless standard-gauge extension between Pittsburg and Antioch, and provides day-to-day management of the standard-gauge Capitol Corridor. A new BART peninsula line, while indistinguishable from Caltrain's service vision, would suck the air out of the emerging pointless debate around the track gauge of the second BART transbay crossing. The Measure RR sales tax can serve as a dowry to integrate San Mateo and Santa Clara counties into a restructured BART district.

Link21, to its credit, places equity and inclusion at the forefront of its project development process. The contrast with DTX is jarring, as TJPA's Phase 2 project can easily be viewed as just another gold-plated white-collar rail project enabling nine-to-five technology and finance types to more conveniently access San Francisco's skyscrapers from the affluent suburbs to the south, without ever having to mix with the blue-collar working class. Bringing DTX under the Link21 umbrella, and merging Caltrain into BART, immediately defuses the classism and racism that underlies this anachronistic Mad Men commuter rail vibe.

Transbay Through Running

A stub-end terminal station suffers from fundamental throughput limits related to long turn times and the unavoidable crossing streams of inbound and outbound traffic in the station approach or "throat." For a given number of platform tracks, a through-running station configuration where all trains that come in one end of the station can exit the other end will always provide more throughput capacity, whether measured in trains per hour or passengers per hour. Trains don't have to dwell any longer than necessary at a platform, and don't foul opposing traffic on their way in or out.

With the DTX as it is, past operational analysis indicated that just 12 inbound and outbound trains per hour (8 Caltrain + 4 HSR) would push the limits of the terminus design, with near-saturated platform occupancy. If you uncork the other end of the train box (by having Caltrans clear some right of way i.e. dismantle and redevelop a couple of medium-rise buildings to the East) so that the DTX can connect directly to a new transbay crossing, everything changes. A lot of new capacity is created by virtue of not having to layover or turn trains right smack where your platforms and track real estate is the most expensive.

A recent through running operations analysis commissioned by the TJPA shows that the Salesforce Transit Center could handle up to 20 trains per hour per direction if no more than six of them turn at the station. Any more than six turning movements, and the excessively long platform re-occupancy times (as the study notes, due to the poor layout of the switches leading to tracks 1-4) will reduce throughput capacity to less than 20 trains/hour.

Broken Assumptions at Link21

The TJPA phasing study reports the following direct quote attributed to Link21 project team:

We have received briefings on the operational modeling for DTX and it would seem that even a three-bay DTX tunnel poses operational constraints. A robust service level through the transbay crossing is required to justify investment into Link21. Link21 is envisioning scenarios where not all trains that cross the Bay would continue to San Jose. At this point, there is no other location to turn trains around in the northern peninsula which makes flexibility in DTX important to the Link21 Program.

You read that right: the Link21 team is thinking of turning Capitol Corridor trains at the Salesforce Transit Center, a completely American idea (copied straight from Penn Station New York) that is operationally insane if you think about it for even a minute. In a through-running configuration, all trains that cross the Bay should stop in downtown San Francisco and get out immediately. The California High Speed Rail Authority is planning a huge yard in Brisbane, a perfect place to clean, service and layover Capitol Corridor trains. These deadhead (non-revenue) moves are much less wasteful of infrastructure capacity than treating a through-running station as a terminal.

As was remarked in previous discussions regarding San Jose, the act of parking or laying over trains at a station platform is the railroad equivalent of parking an empty truck in the middle of a bustling loading zone, and then concluding that the loading zone fails to function adequately. Just stop it, don't even think of turning trains here!

The Bottom Line

Here are the pros and cons of merging DTX with Link21:

 Eliminates silly idea of a multi-gauge transbay tube project Could further delay DTX, since Link21 is at an earlier stage of development
 Increases SFC throughput capacity and bang-for-buck, making the enormous cost of DTX worth it
 Exposes DTX to political re-prioritization
 Provides faster Peninsula - East Bay connections than existing BART, and finally "Rings the Bay with BART"
 Greatly reduces scope and profits for Transportation Industrial Complex
 Makes more efficient use of taxpayer dollars by building  one project and building it right
 Requires inter-agency coordination and mergers, which agencies abhor
Provides seamless regional rail connection from SJ and SF to Sacramento, if Capitol Corridor is electrified

Despite the obvious political and organizational obstacles, from the point of view of a rider and taxpayer, the pros vastly outweigh the cons. The answer is then obvious: the DTX should go down the tubes of a new standard gauge Link21 crossing, with Stadler bi-level EMUs operated by BART seamlessly connecting the peninsula corridor (a.k.a. the new BART Purple Line) directly to Oakland and points beyond. DTX should be built without delay and form the first building block of Link21.

05 September 2021

August 2021 Timetable Review

Caltrain was recently returned to more or less full service, with a timetable that is supposedly simpler (with a claim of just five stopping patterns) and features 104 trains per weekday, the most ever. Let's take a closer look using our handy taktulator, which assigns a timetable a score based on frequency and connectivity. The formulation of the service quality metrics underlying the scores is described here.

Caltrain's 2021 peak hour timetable achieves a score of only 96, meaning the service is slightly worse than the taktulator's baseline, the 2011 peak hour timetable, which a decade ago earned our reference score of 100.

Why so mediocre?

It's mostly in the padding. Caltrain service planners have evidently given up on trying to run a tight timetable while also dealing with the debilitating variability in station dwell times inflicted by the lack of level boarding. The right way to solve this problem was and remains to plan for and implement level boarding, a system upgrade that (on a per dollar basis) has even greater service benefits than electrification. The lazy way is what we see here: about 20% of extra padding is baked into the station-to-station run times, allowing a train to easily make up time and arrive "on time" in the event of a dwell time delay along the way. In the absence of a delay, trains can dawdle along even more slowly than the ancient diesel fleet could manage, and just sit at stations until the clock says it's time to go.

Back in 2005, a baby bullet express with five intermediate stops was timetabled at 59 minutes. In 2015, it was up to 61 minutes. Today, the same express runs in 66 minutes. This follows a pattern noted by Alon Levy on the deterioration of speed.

Another factor that explains the lower score is one fewer train per peak hour, resulting in longer intervals between trains. This helps with fleet size, where only 16 train sets (+2 spares) are needed to operate the 2021 timetable where 18 (+2) were needed before. Two more train sets are freed up for maintenance downtime, a vital bit of breathing room as Caltrain's older diesel fleet is breaking down more often. The fleet is well past its expiration date due to the multi-year delays in the electrification project.

Is it optimal?

Can a timetable be devised that uses no more than 16 (+2) train sets and scores better than 96? Why yes it can. Here is a Silicon Valley Express timetable that uses just 14 (+2) train sets with four trains per peak hour per direction, and scores 102.

Why is it better? First, it follows census patterns and puts the stops where they link the most residents and jobs, not where there is the most parking. It is more regular and has fewer gaps with long waits. While this does not figure into the service score, it makes far better utilization of the train fleet (83% of the time in revenue service, versus 70%). More efficient fleet utilization leads to fewer trains and fewer crews being needed to provide the same service, reducing labor and maintenance costs per passenger mile. All this is done without any magic: 15-minute equipment turns, comfy 40-second station dwells and a slightly less absurd padding level of 15%. There are zero overtakes, so fewer opportunities for cascading delays. Finally, this timetable is much simpler to understand for a rider, having just two service patterns.

One can only hope that despite this interim state of mediocrity, Caltrain will successfully implement its "moderate growth" service vision, which scores an impressive 240. Getting there will require reliable 30-second dwells for which level boarding is a must.

Credit to Richard Mlynarik who did the time-consuming part of this analysis.