19 January 2018

CalMod 2.0: Three Things to Watch

Caltrain was recently reported to be seeking another $630 million grant from California's cap and trade program to eliminate diesel trains entirely and to increase the passenger capacity of the new EMUs a decade earlier than previously envisioned. A previous board agenda alluded to a $756 million program known as CalMod 2.0, consisting of:
  • Full conversion to 100% EMU + capacity increase ($440M)
  • Broadband ($30M)
  • Maintenance facility improvements ($36M)
  • Level boarding and platform extensions ($250M)
While the amount reported in the press doesn't match the CalMod 2.0 tally, there may be other funding sources on tap and we are probably looking at the same package of improvements. The EMU fleet expansion is an exercise of the fully priced option for 96 additional EMU cars under the existing contract with Stadler.

There will be three important issues to keep an eye on:

1) Level Boarding

Level boarding is the logical next step after electrification, and a perfect complement: where electrification reduces time in motion, level boarding reduces time at rest. Every second of trip time saved is equally valuable, which is why cutting station dwell times is enormously important.

Not all level boarding solutions are created equal, and it's not enough for the height of the platform to equal the height of the train floor. To enable dense "blended" traffic on the peninsula corridor, what Caltrain needs is unassisted level boarding where persons of reduced mobility can board without the help of a conductor across an ADA-compliant gap. That means NO bridge plates, NO exterior lifts, and NO conductor assistance.

While the new EMUs will have the ability to dock at 51" platforms, staff and consultants evidently do not agree on a path forward towards system-wide level boarding. With a nine-figure amount being contemplated for platform extensions and level boarding under CalMod 2.0, the approach and transition strategy needs to be straightened out, and soon, to avoid enormous "do over" costs. And we should not let Caltrain claim that platform extensions for 8-car trains will cost a lot: the real price tag for that is in the range of $25 million.

2) Short EMUs for Frequent Off-Peak Service


Base order (blue) and option order
(orange) show fleet composition
for 100% electric service
The sort of service that Caltrain wants to run in the future, currently being discussed in the context of a nascent business plan, will determine the specific composition of the 96-car option order, i.e. how many of what EMU car type to buy. The wrong fleet decision could very well preclude service patterns that may be deemed preferable once the business plan effort concludes, which is why CalMod 2.0 needs to be carefully considered not to overtake or conflict with the business plan effort. That being said, you don't need an army of consultants to figure out what fleet Caltrain will need.

Use case #1: during rush hour, to run a 70 minute SF Transbay - South San Jose schedule at 6 tph per direction with 20 minute turns at each end, you need (70+20)/60 * 6 * 2 = 18 trains in service, plus one extra train available at each end of the line to protect against cascading delays, or 20 trains available for service. Allowing for a couple of trains to be down for maintenance, we need 22 trains total @ 8 cars each.

Use case #2: off-peak service running at 80 minutes SF Transbay - South San Jose at 3 tph per direction with 20 minute turns at each end, you need (80+20)/60 * 3 * 2 = 10 trains in service, plus one extra train at each end, or 12 trains available for service. Throwing in another two trains down for maintenance,  we need 14 trains total. Because it's very expensive to haul around empty seats, these must be short 4-car trains.

Supporting both of these use cases within the overall size of the Stadler order (96 cars base order + 96 cars option) requires the option order to consist primarily of 4-car EMUs, as shown in the figure at right. At peak times, 4-car EMUs would operate in pairs, mixing with the rest of the 8-car subfleet. If needed in the long term, EMUs could be extended to 12 cars by coupling 8 + 4 cars.

3) Just Say No to a Third Bike Car

Bringing a bike on Caltrain is one of the finest ways to commute; your author has done it hundreds of times. The bikes-on-board community is already gearing up to pressure Caltrain into adding a third bike car to the future 8-car EMUs, deeming the two bike cars in the base order 6-car EMUs to be inadequate. The typical argument goes that any bike "bumped" is a paying customer left behind, which is a logical argument when spare capacity is available. However, with trains at standing room only peak loads (by design!) there are plenty of potential non-bike passengers left behind. They are not "bumped" in the literal sense, since they don't even show up at the train station. Here's why: when the cost of enduring a crowded train trip becomes unbearable, the invisible hand of supply and demand pushes more and more potential riders to drive instead.

Under SRO conditions, every free bike space on the train displaces a paying passenger, a sort of "reverse bumping" effect that explains quite elegantly why, for example, the Paris RER does not and should not have dedicated bike cars. Caltrain has gone quite far enough in providing free bike space on board, and should not have a third bike car in 8-car EMUs, in everyone's interest of maximizing peak passenger capacity. In the long term, bike commuters will benefit more from world-class bike parking.

25 December 2017

CBOSS Dumpster Fire Update

The CBOSS development lifecycle,
as anticipated in 2009 on this blog.
Today we are at "point of no return."
The deadly crash of an Amtrak train near Tacoma, Washington, which would likely have been prevented if a PTC (Positive Train Control) system had been in place, has renewed the discussion of the status of PTC systems in the Bay Area. Caltrain officials say everything will be OK with CBOSS, Caltrain's very own flavor of PTC. Despite those assurances, a potent brew of ingredients is mixing together.

Bonfire of Lawsuits: After a well-chronicled program failure involving delays, cost overruns, and failure to meet milestones, Caltrain terminated the CBOSS prime contractor, Parsons Transportation Group, in February 2017. PTG and Caltrain promptly sued each other, with PTG claiming wrongful termination and Caltrain seeking up to $98 million in damages. A rich trove of documents can be accessed online under San Mateo Superior Court case number 17CIV00786, and chronicles in detail everything that went wrong with the CBOSS program. With Caltrain likely to recover some damages, PTG has now sued Alstom (formerly PTG's subcontractor and the supplier of CBOSS hardware and software) for failure to deliver a working solution. One is left to wonder how this motivates Alstom to finish the CBOSS project, since delivering a working solution to Caltrain would undermine the claim that Alstom was given an impossible task.

Dying Product: The hardware and software underlying CBOSS is known as I-ITCS, a product originally developed by GE Transportation Systems Global Signalling. While a precursor known as ITCS briefly operated on Amtrak corridors in Illinois and Indiana, it is now being displaced by the de-facto standard freight PTC system known as I-ETMS, with ITCS relegated to controlling only the grade crossing functionality in these corridors. Alstom, which acquired GE Transportation Systems in 2015, is not likely to see a future in the I-ITCS product, leaving Caltrain with a globally unique hardware and software solution. This does not bode well for product support over the lifetime of CBOSS.

Looming Deadline: the deadline imposed by Congress and the Federal Railroad Administration to successfully complete a PTC revenue service demonstration is just a year away, at the end of 2018. One year is not enough to finish, and Caltrain will almost certainly blow this deadline. Will FRA grant another extension and allow Caltrain to continue operating without PTC?

Sole Source Savior: in July 2017, avionics firm Rockwell Collins' subsidiary ARINC was awarded a sole source contract to figure out what it will take to pick up the pieces and complete the CBOSS project. ARINC completed this assessment in September, and will soon (by sheer programmatic necessity, since failure is not an option) be awarded a name-their-price sole source contract to finish a minimally working version of CBOSS that passes FRA muster. With the leverage that ARINC enjoys under these circumstances, the "re-procurement" of CBOSS will likely be (1) expensive and (2) structured such that Caltrain bears all of the risk of continued failure, i.e. cost-plus-fixed-fee rather than fixed price. With the clock ticking, the re-procurement effort has already fallen behind the planned fall 2017 schedule.

Budget Crunch: To date, Caltrain has spent over $200 million (yes, one fifth of a billion dollars!) on CBOSS with nothing to show for it. All the money allocated for CBOSS is spoken for, and a lot more (several tens of millions) will be needed to finish the project. Some of that will come from damages, but it is quite likely that 2018 will bring emergency financial maneuvers to throw more good money after bad.

Descoping of Functionality: while the first 'I' in Caltrain's I-ITCS solution stands for "Interoperable," which was one of the original selling points of CBOSS, this feature is now being thrown over the transom. Interoperability requirements contributed to the scope creep that triggered a re-design of the supposedly off-the-shelf ITCS software. It didn't help that Union Pacific was (as per usual) actively non-cooperative in helping to develop an interoperable solution, leading to Caltrain throwing in the towel and spending an additional $21.7 million (from an FRA "interoperability grant," no less!) to dual-equip seven diesel consists with the I-ETMS freight PTC system for operating on the Gilroy branch owned by UPRR. How I-ETMS freight trains will be accommodated on the peninsula corridor in I-ITCS territory is a burning question, for which the range of answers includes ditching I-ITCS and replacing it with the more viable I-ETMS, following the Amtrak example.

System Integration and Testing is Hard: while Caltrain never fails to remind us that all of the components of CBOSS are physically installed on the trains and the tracks, that is the easy part. The hard part is getting everything to operate together reliably every day, and Caltrain and their shifting band of contractors are barely getting started on this most difficult phase of the development of a new and complex safety-critical system. Integration and Testing is where the best design intentions meet cold harsh reality, and all the mistakes and omissions made during the design phase become painfully apparent. While PTG claimed in court filings that they were 90% done with CBOSS when their contract was abruptly terminated, that last 10% of troubleshooting commonly takes far more than 10% of the budget or schedule.

PTC is Hard: the legal declarations from PTG managers who ran the CBOSS program (see 17CIV00786) reveal a long list of underlying factors that caused much acrimony and remain unchanged today: (1) the specifications and standards for PTC continue to evolve, triggering continued changes and penalty testing; (2) Caltrain and its in-house consultants (the so-called "owner's team") are woefully ill-equipped and uncoordinated in their approach to complex safety-critical avionics technology development; (3) the formal contractual interactions between the "owner's team" and the vendor are complicated and delay-prone; (4) working with UPRR is a huge pain in everyone's caboose; (5) the underlying systems over which CBOSS is supposed to "overlay" are kludged-together stove pipes that, incidentally, will require nearly total re-design for the electrification program; (6) testing PTC on an operating railroad requires extensive coordination that has been demonstrated to be lacking; and so on. Strike PTG and substitute ARINC.

These ingredients will produce a situation where CBOSS does less than was promised, later than planned, and for a lot more money. No crystal ball is needed to predict that CBOSS will continue to "fail forward" to a finish line somewhere beyond 2018.

26 September 2017

Thoughts on Palo Alto

There is a vigorous discussion of grade separations now underway in Palo Alto. It misses several important points:

1) Grade Separation is not one project. Trying to come up with a single, grand unifying grade separation scheme for the entire rail corridor through Palo Alto is to over-constrain the problem and to limit the range of feasible solutions. The wide geographical spacing of the four remaining grade crossings in Palo Alto leads naturally and logically to three separate and independent projects: Alma, Churchill, and Meadow/Charleston. These three projects can be and should be completely decoupled from an engineering perspective, if not from a political perspective. The underlying geometry of Palo Alto does not lend itself to a single project.

2) Creating new cross-corridor access is not grade separation. While it is understandable that the city desires to knit together neighborhoods on opposite sides of the track by creating new places ("trench caps") where people can access the other side of the corridor, this is not grade separation and should not be funded by scarce grade separation or transportation dollars. It can't be said that the city was actively divided by the rail corridor, since the rail corridor was in place decades before Palo Alto grew into a city. While everyone agrees that new cross-corridor access would improve Palo Alto, the distinction of scope between grade separation of existing crossings (today's network topology) and new cross-corridor access (tomorrow's network topology, a nice-to-have) should remain crystal clear. Muddling the project scope will muddle the discussion of funding.

3) Split-grade solutions should be studied with due diligence. When the city commissioned a grade separation study from engineering firm Mott Macdonald, the council deliberately excluded from consideration any designs where rails or roads might rise above existing grade. From the outset, this eliminated the standard solution that every other peninsula city has adopted: San Bruno, Burlingame, San Mateo, Belmont, San Carlos, Menlo Park and Sunnyvale either already have or are planning split grade separations, where the rails are raised a bit and the streets are lowered a bit. Turning a blind eye to split grade solutions, however controversial they may be, casts doubt on the entire decision making process. Without due diligence in studying a full range of grade separation solutions, the politics of assembling the necessary funding will become unnecessarily complicated.

4) Funding matters. The most expensive options are the most popular because the cost isn't yet borne by anyone. Everything is paid for with OPM or Other People's Money. If you went to a restaurant with OPM, of course you would select the Filet Mignon (or truffles, if you're vegetarian). A selection process that ignores funding is detached from reality. This also means teaching people about orders of magnitude: capturing ill-defined revenue from new uses of 45 acres of highly impaired land that the city doesn't own, even at Palo Alto prices, doesn't begin to pay for the astronomical expense of burying the tracks. Until funding is seriously factored into decision making, it's all just unicorns and rainbows.

5) County grade separation funding is always at risk. While 2016 Measure B set aside $700 million for grade separation projects, a 3/4 majority vote of the VTA board is all that it takes to re-program some or all of that funding "as circumstances warrant" towards BART, in the exceedingly likely event that the San Jose extension goes over budget. Spend it soon, or flush it into a giant sink hole in San Jose.

Failing to properly acknowledge these realities will likely leave Palo Alto's decision making process tied in knots as other cities move forward.

12 August 2017

Freeway Lanes of Caltrain

If everyone drove instead of taking Caltrain, how many more lanes would peninsula freeways need to absorb the additional traffic?

The way to answer this question is to count how many train passengers ride past any given location, in each direction, within the span of one hour. Caltrain publishes all the information you need to do this calculation rigorously, without making any assumptions: the timetable tells you when each train passes each location, and the 2016 weekday passenger count by train tells you how many people are on board that train at that time.

Four cases are considered: morning northbound, evening northbound, morning southbound, and evening southbound. Rather than picking a fixed morning and evening hour over which to count passengers, we slide a one-hour window across the peak period until we find the peak hour at each location, during which the most passengers ride past. Caltrain operates five trains per hour per direction repeating on an hourly cadence, so we never count more than five trains in the totals.

It is an easy but tedious calculation, perfectly suited for a computer.  This is what pops out:


This graph reveals many of the features noted in ridership reports: the flow is asymmetrical with more riders traveling northbound AM / southbound PM, the Gilroy branch is dead, Stanford generates enormous ridership, etc.

Translation to Freeway Lanes

To convert the number of Caltrain passengers into freeway lanes, very few assumptions are needed, and those we need can be backed up by references.
  1. A congested freeway lane operating at 45 mph can carry 2000 passenger cars per hour, according to the Federal Highway Administration's HPMS Field Manual (Parameter values: FFS = 45 mph, BaseCap = 2150 pcphpl, PHF = 0.95, fHV = 0.98, fp = 1.0).
     
  2. The average vehicle occupancy (AVO) is 1.3 people, based on two studies of the 101 corridor in San Mateo County. This figure includes buses, van pools and corporate shuttles.
This means a single freeway lane can theoretically carry 2600 people in one hour. Note this is a very optimistic figure because slight perturbations in the flow of traffic can cause slow-downs that reduce throughput due to lower free flow speed (FFS). But we'll use this very high number to make an extremely conservative estimate of how many lanes of freeway can carry all of Caltrain's ridership.

Freeway lanes typically do not change directions to accommodate peak flows. That means we must consider northbound lanes separately from southbound lanes, with no possibility of re-allocating the lane capacity to accommodate the AM/PM flow asymmetry that is observed on Caltrain. In practice, this means we must add the northbound peak flow (AM or PM, whichever is highest) to the southbound peak flow (again the highest of AM or PM) to size the number of equivalent freeway lanes. Looking at the graph above, which shows the highest flow is northbound AM and southbound PM, we must add AM northbound and PM southbound people per hour, and divide by 2600 people per hour per freeway lane. Here is the result:


So as of 2016, plain old diesel Caltrain equals about 2.5 lanes of freeway, including both directions. If you integrate the area under this curve, you get how many lane-miles of freeway would be needed to replace Caltrain. That number is 119 lane-miles. These are very conservative lower bounds.

When you hear the argument that "millions" of people use highway 101 but only about 30,000 people use Caltrain, shut it down with facts: today Caltrain amounts to 2.5 / 8 or at least 30% of the lane capacity of highway 101 during rush hour. The reply might be that not all those people would end up on 101, but with an average trip length of 23 miles, which driver wouldn't use a freeway?

Future Capacity Implications

Caltrain capacity is set to increase considerably, first by ~30% with the initial electrification and modernization project, and by ~60% once the system is running at 6 trains per hour with 8 cars each. (If you don't count standees, those figures are ~10% and ~25%, but why would you not count standees?) A 60% capacity increase is equivalent to one and a half lanes added to the entire length of highway 101 from San Jose to San Francisco.

It doesn't have to stop there: more trains per hour and longer trains are possible, because EMU trains scale up in a way that diesel can't. A future Caltrain capacity increase to about 10,000 passengers per peak hour per direction (about triple today's throughput) isn't out of the question, does not require adding tracks or expanding the rail corridor, and would equate to adding 5 new freeway lanes.

In certain quarters of Silicon Valley that are enamored of Hyperloops, self-driving Teslas and Boring underground tunnels, electric Caltrain is looked down upon as a last-century technology that is about to be made obsolete. That particular outlook fails to grasp the importance of throughput or to recognize the enormous carrying capacity of modern electric rail. Self-driving Teslas and Hyperloops will achieve dismal throughput capacity as measured in passengers per hour, and no amount of whiz-bang technology will change the underlying geometry of this increasingly urban region.

The way forward is to add more freeway lanes of Caltrain.

03 July 2017

The Overtake That Won't Be

In its renewed environmental review process for the San Francisco to San Jose project, the high-speed rail authority is considering the alternatives for the peninsula rail corridor. The outlines of the new draft EIR are emerging, and this is where politics meets engineering.

Interested stakeholders keep asking about how the blended system will actually work, with Caltrain and high-speed rail sharing the scarce resource that is track capacity. The issue is being studied in some detail behind closed doors by an entity known as the Joint Scheduling Working Group (JSWG), consisting of experts from HSR and Caltrain aided by their respective consultants. As of the end of 2016, the JSWG had produced a first report on its work, which was shaken loose by a public records request from CARRD. Before digging into this, let's take a look back at how we got here.

2012 Blended Operations Analysis (Caltrain/LTK)

While the original four-tracks-all-the-way HSR plan was collapsing in a firestorm of community opposition, Caltrain commissioned a study of blended system operations (8 MB PDF) from consultant LTK Engineering Services, to see if blending Caltrain and HSR primarily on the two existing tracks was viable. The 2012 study concluded that without any additional tracks, the corridor could support up to 6 Caltrain + 2 HSR trains per hour per direction, increasing to 6 Caltrain + 4 HSR with overtake tracks.  Key results were:
  • With speeds limited to 79 mph, the most reasonable option with 6 Caltrain + 4 HSR was a "short middle overtake" between Hayward Park (San Mateo) and Whipple Ave (Redwood City).
  • A "long middle overtake" all the way through Redwood City provided only marginal performance improvements.
This study legitimized the blended system, which has ever since been the favored approach to bringing HSR to the peninsula rail corridor. The study contained numerous disclaimers to the effect that no official decisions had been made regarding future service levels, programmed overtakes, stopping patterns or scheduled trip times... all the important considerations that feed into a railroad's product, namely its timetable.

2013 Additional Blended Operations Analysis (Caltrain/LTK)

A short while later, LTK published another report (2MB PDF + 14MB Appendices) that can best be characterized as an expansion and refinement of the 2012 analysis, considering additional options. Key results were:
  • Unlike the 2012 study, the "long middle overtake" performed significantly better than the "short middle overtake."
  • A new option, the "middle 3-track overtake" (between San Mateo and Palo Alto) performed almost as well in simulation, although it assumed all HSR trains entered the corridor on time, unlikely in practice.
  • Other overtake track options did not fare as well.
The disclaimers continued, with the conclusions of the study being described as "educational."

2016 Joint Schedule Working Group Report (HSR/SMA)

The key chart in the SMA study
(PDF page 62 / slide 48)
The JSWG was established in April 2016, a while after HSR had engaged the services of Swiss rail consultancy SMA. To avoid a standoff between dueling agencies and consultants, Caltrain/LTK and HSR/SMA are now comparing notes on their respective plans for the blended system. The JSWG's 2016 draft year end report (10 MB PDF) provides important context to the decisions now being made to select a "preferred alternative" for the HSR blended system EIR. This study is interesting for three reasons: it is the first blended system study led by HSR, it offers insight into the evolving ideas of the JSWG, and it is not sugarcoated because it wasn't intended for wide public distribution. Key results were:
  • The "no additional passing tracks" case is shown to support 6 Caltrain + 4 HSR per hour per direction, unlike in the LTK studies, provided that headways are tightened and Caltrain passengers don't mind sitting in a siding for 6 or 7 minutes during these overtakes.
  • The "short middle 4-track overtake" degrades Caltrain trip times, since overtakes don't naturally tend to occur there.
  • The "middle 3-track overtake" performs better than any other option, thanks to allowing bidirectional operation through almost its entire length, unlike in the LTK study where half the length of the overtake track was dedicated to each direction.
Tea Leaf Reading
The grotesque station-in-the-sky
proposed for San Carlos under
the short middle 4-track option
The constant refrain that nothing has been decided yet continues to this day, but the tea leaves are becoming quite readable. Here is some informed speculation:
  1. The HSR team really, really doesn't want to build the "short middle 4-track overtake," generally because they have no money and specifically because the SMA analysis has shown this scenario to be a poor performer operationally.
     
  2. However, the HSR team is reluctant to withdraw any alternative this late in the preparation of an EIR, after it was carefully introduced to the public through countless outreach meetings, workshops and open houses. Sudden change scares people.
     
  3. In order not to build the "short middle 4-track overtake," the HSR team has engineered it into a straw man alternative, using the prospect of grotesquely massive concrete viaducts towering fifty feet over San Carlos and Belmont to strategically elicit vigorous public opposition. It's working, but unbeknownst to them, San Carlos and Belmont have little to worry about.
     
  4. Due to having no money, the HSR team strongly favors the "no additional passing tracks" alternative. The mediocrity of the resulting Caltrain timetable, and the amount of time spent by Caltrain passengers waiting to be overtaken, is of little concern to them. But that's okay, since San Carlos and Belmont made them do it.
     
  5. The HSR team probably dreads resistance from Caltrain stakeholders who don't want the peninsula rail corridor being taken over to Caltrain's detriment. Strong resistance could force the HSR team to revive the "middle three-track" alternative that had previously been eliminated from the EIR process (see slide 15 in this outreach presentation), setting back the environmental review schedule.
     
  6. If the assumptions in the SMA analysis stand up to closer scrutiny, the "middle three-track" scenario could actually be a viable compromise for the blended system. It would no doubt be expensive due to the number of new grade separations, but the result (if one believes SMA) would be fast and robust service for both HSR and Caltrain, with reasonably-sized grade separations in every town from San Mateo to Palo Alto. In the last year, the winds of public opinion have turned more favorable to grade separations in Menlo Park and Palo Alto.
One thing is sure: the "middle three-track" alternative should be added to the HSR EIR and studied in detail, with an eye towards designing the future blended system timetable. The timetable is the product, and it will soon be time to decide on one.