Census Driven Service Planning

The diagram at right shows where people live and work along the entire length of the rail corridor from San Francisco to Gilroy, as extracted from government census population and jobs data sets.  The diagram is also available as a PDF.

Implications for Rail Service Patterns

By simple observation of the features of the census population and job distributions along the peninsula corridor, it is possible to infer the desirable features of train service patterns that will maximize commute ridership.

1. Transbay has more than 100,000 jobs within a half-mile radius (more than every other station in the system combined). The concentration of jobs near San Francisco's Transbay Transit Center cannot be understated. This station absolutely must be served by each and every train, and it would be highly counter-productive to terminate any train at 4th and King.
    
2. Silicon Valley shows up in the jobs distribution as a broad hump, mostly homogeneous and stretching from Palo Alto to San Jose.  To serve this rich but diffuse commute market, all trains should make every stop in Santa Clara County.  There should never be any skip-stop service here, and the wider spacing of stops (relative to San Mateo County) will result in only minor trip time penalties.
    
3. San Mateo County has numerous stops, spaced more closely together and with middling jobs and population density.  To enable faster service to and from San Francisco and Silicon Valley, it makes the most sense in this portion of the corridor to operate skip-stop express service alongside local service.
    
4. South San Jose, while south of Silicon Valley, has a massive and untapped residential market that can serve as origin to jobs further north.  Tamien currently functions as a slow and infrequent addendum to the peninsula service, but should be sped up and extended to Blossom Hill.
    
5. Oakdale in San Francisco opens up a new residential market for Caltrain.  The distribution of people nearby is even denser than at 22nd Street.
    
6. The Gilroy extension doesn't make much sense.  There are so few jobs and people here that Caltrain (as primarily a commuter service) should not run to this area.  Serving Morgan Hill and Gilroy is best left for a long-distance operator such as Amtrak California.

Putting all this together, what would a service pattern look like that is tailored to the census distributions, to maximize commuter ridership?  First, it would not look like today's Baby Bullet, which severely under-serves numerous stops.  It would also look very different from Caltrain's latest planning fad, the "peak-period skip-stop zone express," used as the basis for all operational simulations in the blended service analyses published to date.  It would look like this, with distances drawn to scale:

• The Silicon Valley express links the major employment centers of San Francisco and Silicon Valley, highlighted in orange, providing a faster and better alternative to fleets of white luxury buses stuck in traffic on US 101.  It would run every 15 minutes.
   
• The San Mateo local serves all the minor stops throughout San Mateo County, terminating and originating across the platform from the Silicon Valley express at Redwood City.  This provides fast and penalty-free transfers between Silicon Valley and cities all along the peninsula.  The local turns back in Redwood City, minimizing crew and fleet requirements while still providing service every 30 minutes.
   
• Stops in San Francisco and San Jose that have very large residential markets are served in the peak commute direction only.

This service pattern is also well-suited to future blended HSR service: a southbound high-speed train and a closely-following Silicon Valley Express can overtake and catch up (respectively) with a San Mateo local by using a four-track mid-line overtake facility constructed from San Mateo to Redwood City.  Because the local turns back at Redwood City, it does not impede traffic in Santa Clara County.

The time has come to fundamentally rethink peninsula rail service patterns.  Caltrain's "peak-period skip-stop zone express" is almost certainly not the best solution for meeting future demand; a much wider range of options must be considered.

Level Boarding Forum

A few days ago I participated in a panel discussion hosted by Friends of Caltrain on the topic of level boarding and platform compatibility with HSR.  Here are the slides I presented to stimulate the discussion, available either as a 7 MB PDF file or on Scribd:

Level Boarding for Caltrain by clemtillier

It was a good discussion, and I came away with the following impressions.

Things that surprised me in a good way:

• Caltrain is finally considering the possibility of level boarding, although no funding has been identified.
• Bryan Dykes, from the Transbay project, was quite supportive of shared platforms and further pointed out that a bigger constraint on capacity comes from the excessively long platform dwell times requested by Caltrain and HSR.
• The escalator pits on all three platforms of the Transbay Transit Center are built to accommodate any platform height.
• Ben Tripousis of the HSR Authority stated that fare collection and security issues were not necessarily show stoppers for shared platforms, and that platforms could conceivably be shared provided they are built to HSR specifications.

Things that surprised me in a bad way:

• Caltrain has not started the waiver process for CPUC General Order 26-D, although they have acknowledged the potential need to do so.
• Marian Lee of Caltrain stated that Caltrain's reasons for wanting to terminate some trains at 4th and King is to serve certain markets there (presumably in reference to Giants games).  I didn't have a chance to question further, but they seem to be missing that every Transbay train would also stop (underground) at 4th and King-- it's not an either-or, it's one or both.
• Caltrain seems eager to roll out the red carpet for any "tenant railroad" that comes calling.
• The three agencies are clearly not communicating enough about this issue to support the important decisions that Caltrain needs to make very shortly for its new vehicle procurement.

Things that didn't surprise me:

• HSR is going with high platforms, period.  That particular train has already left the station, and there will be no turning back from the joint procurement with Amtrak.  If platforms are to be shared with HSR, they will be high platforms.
• HSR cites as justification for the massive station complex in San Jose that numerous tenant railroads (the "downstairs folks" such as ACE and the Capitol Corridor) plan massive expansion that will need a lot of track and platform space.
• People in the advocacy community are not in agreement on the need for platform sharing.  Some believe that Caltrain needs low (~25") platforms more than it needs platform sharing with HSR at Transbay or anywhere else.

It all came down to this in the end: high platforms, or segregated platforms--pick your poison.  I happen to believe that high platforms will be the lesser of these two evils.  What do you all think?

Beyond Level Boarding

It thankfully happened: after all these years, Caltrain has finally stated something (anything!) about level boarding.  This is an improvement that has long been neglected in favor of the more flashy electrification project.

Around here, level boarding has been discussed several times already, so here are a few oldies but goodies from the archives:

1. Platform height: background and compatibility issues
2. How platform incompatibility results in oversize stations
3. Platform sharing issues between Caltrain and HSR
4. How platform incompatibility is making a mess at SF Transbay
5. Platform height: the full collection of articles from this blog.  Read it and weep.

There is also a nice APTA overview presentation that goes into some detail about the conflicts between level boarding and freight trains.

Caltrain's presentation sums up the main advantage of level boarding in one bullet point, "Operating efficiencies," without clearly stating why it's so important.

• Level boarding reduces trip times.  Without steps, passengers can board and alight far more quickly and the train can save about 15 seconds of dwell time at every station stop.  For an all-stops local, this starts adding up, and saves about half again as much as much time as saved by switching from diesel to electric!
   
• Level boarding reduces delays.  Wheelchairs, bikes, strollers, hordes of drunk Giants fans, airport travelers with suitcases, everybody can get on and off far more quickly and easily.  As any rider will tell you, station dwell times suffer from a statistical "long tail" of agonizingly long station dwells due to a variety of these factors, a sort of station dwell Russian Roulette.  The only way to run this railroad is to add plenty of timetable padding to absorb these anomalies without making a mess of cascading delays.  Fast forward to 2030: under a blended scenario where hourly traffic is doubled on largely the same tracks, this is no longer acceptable.  Station dwell times must be predictable and reliable to avoid making a mess of the morning rush, and level boarding isn't just a nice-to-have; it is a must-have.

Caltrain's tentative plan is to study the possibility of converting all station platforms to 25 inches above rail (up from today's 8 inches) by some unspecified time in the future, and to let high-speed rail have its own set of separate platforms, most likely at 48 inches above rail.

Beyond Level Boarding: Platform Sharing

Level boarding as envisioned by Caltrain is not a trivial undertaking.  It will be expensive, because dozens of platforms will have to be entirely rebuilt.  It will be politically difficult, not in the least because state regulations will need to be overhauled over the strenuous objections of freight railroads.  It will be time consuming, because so many platforms can't be rebuilt overnight.  It will be logistically complicated, because the system will have to continue operating during the transition with a mix of platform heights.

Why not go a tiny bit further to achieve far greater benefits, at far lower cost?

Platform sharing is the next step beyond level boarding, where Caltrain and HSR can share the same platforms at San Francisco, Millbrae and San Jose.  Platform sharing has distinct advantages that have been discussed at length on this blog.  Platform sharing between conventional trains and high-speed trains is already practiced everywhere in the world, except in those countries where track gauge precludes it.

• San Francisco Transbay is where all the action will be.  There are more jobs within a half mile of Transbay than there are within a half mile of each and every Caltrain stop, combined!  Service into and out of this tiny six-track terminal station will be inherently inefficient but crucially important for both Caltrain and HSR.  Platform sharing would increase Transbay capacity for decades into the future.
   
• Millbrae is where the HSR consultants once expressed interest in building a $1.9 billion dollar tunnel to shoehorn new platforms between a handful of residential properties and the existing BART station, which incidentally cost only about $0.1 billion to build.  Never mind the sheer fiscal insanity of it: platform sharing would allow the station to serve both Caltrain and HSR within its existing footprint.
   
• The mid-peninsula HSR stop would be nothing more than another platform where a high-speed train happens to stop, should that be deemed advantageous.
   
• San Jose is where the HSR plans get truly loopy: they want to build a massive station up in the sky over the existing station, hovering on a forest of concrete straddle bents, with a six-mile approach viaduct to the north and an "iconic bridge" (Bay Bridge east span, anyone?) to the south.  Platform sharing would enable both HSR's and Caltrain's needs to be met on a single level, at grade, within the existing footprint of the station.  This would save billions of taxpayer funds that the HSR authority seems to be rather short of.

Why are the respective agencies here not talking about platform sharing?  There is bureaucratic inertia and a general unwillingness to coordinate, sometimes verging on outright hostility.

How To Pull It Off

1. Get HSR to back off from the airport-like notion of separate, dedicated platforms.  Building a TSA security perimeter around the HSR system while leaving Caltrain open won't prevent mass carnage, any more than locking the doors on only one side of your car will prevent theft of your belongings.  HSR can be built far more cheaply with platform sharing.  Of course, none of these measures would be favored by the for-profit Transportation Industrial Complex.
    
2. Get Caltrain to back off from the idea of 25 inch platforms.  Not all bilevel EMUs must have low doors; some of the latest models work with high platforms, and there are smart ways to facilitate a height transition by adding additional doors to the EMU fleet.  Or try another way: get HSR to adopt a 25 inch standard; good luck with that.  And please, don't myopically plan everything around the Bombardier fleet staying until 2030.
    
3. Get the Transbay JPA and San Francisco to understand the economic advantages of platform sharing: a busier, more efficient and more commercially successful terminal, and the opportunity to reclaim much of the under-utilized train parking at 4th and King for redevelopment.

None of these challenges are technical.  They are institutional and political.

2013 Q2 Corridor Roundup

original photo by afagen

There's been no shortage of developments in recent months on the peninsula rail corridor.

The Caltrain/HSR Blended Service Plan/Operations Considerations Analysis was published on the Caltrain website.  This document aims to flesh out the 2012 Caltrain/HSR Blended Operations Analysis with more detail requested by stakeholders.  While the comment period for this document is now closed, it has a number of weaknesses that should be addressed.

1. Strange assumptions about service to San Francisco's Transbay Transit Center.  For some obscure reason (agency turf?) all of Caltrain's simulations (see string charts in appendix, starting at page 29) send just two out of six trains per hour into Transbay, where essentially all the ridership will be.  Most Caltrain traffic is assumed to terminate outside the financial district, at 4th and King.  The string charts do not show any conflicts that would prevent sending at least four (if not all six) trains per hour to Transbay, making full use of the triple tracks in the downtown extension tunnels.
   
   If you accept that Caltrain isn't trying to spite its customers or diminish its own fare revenue, it's hard to imagine why any train would still terminate at 4th and King when it doesn't absolutely have to.
    
2. Strange assumptions about Caltrain station dwell times.  While the station dwell times of today's Caltrain service have been studied in excruciating detail, the way the dwell time statistics were incorporated into the simulation model may leave something to be desired.  Dwell times are the only randomized input to the model, and the specific random distribution used to calculate them can have enormous impact on the results.
   
   Because of Caltrain's 8-inch platforms and inefficient passenger flows, dwell times can occasionally exceed two minutes, for example if a wheelchair user needs to board a train.  The resulting dwell time random distribution has a long tail that reflects the "Russian Roulette" nature of today's operations.  These occasional outliers can easily ruin a tight timetable by setting off a domino effect of delays to other trains, resulting in poor on-time performance.  This is especially important because on-time performance (measured in minutes of delay), the figure of merit used to evaluate different operating scenarios, becomes sensitively dependent on the choice of dwell time random distribution.
   
   Consider level boarding, an improvement that Caltrain hasn't yet discovered how badly it needs.  The lack of steps and abundance of doors makes dwell times shorter and, more importantly, far more predictable.  The dwell time random distribution for level boarding does not have the long tail used in Caltrain's simulations, and we can finally stop playing Russian Roulette.  Look no further than BART to get representative dwell time data.
   
   What is the effect of the long tail in the dwell time random distribution?  Would level boarding be a better investment than building more passing tracks?  We'll never know, unless the model is re-run with a different dwell distribution that simulates level boarding.
    
3. Strange assumptions about the "hold out" rule.  This operational rule mandates that when a train stops at an old, narrow center-boarding platform, no other train may enter the station until the first train has departed (otherwise bad things can happen).  The practical effect of this rule is that trains operating on separate tracks can delay each other.  The hold-out rule is slowly turning into an exception as stations are modernized, and today applies at only three stations: South San Francisco, Broadway in Burlingame, and Atherton.
   
   In a cute computational flourish, the hold-out rule was accounted for in all operational simulations in the Caltrain report, but nobody bothered to ask if it would make any sense to invest billions (with a 'B') in the peninsula corridor to build HSR passing tracks, all the while not spending a few million (with an 'M') to rebuild the three remaining platforms to retire the hold-out rule forever.  Worse, Caltrain's analysis made no attempt to tease out the effect of the hold-out rule on minutes of delay, to quantify its effect relative to other sources of delay.
   
   This shortcoming could easily be remedied by re-running the model with and without the hold-out rule.

Finally, the document reveals a stunning discovery in its analysis of Dumbarton service:

It is important to note that the feasibility of operating Dumbarton Rail Corridor service on the Caltrain corridor in addition to the Caltrain and HSR blended system does not equate to having the capacity to add another Caltrain or HSR train during the peak hour. DRC service fits because it uses only portions of the corridor and does not require an end-to-end corridor operating slot.

This is the exact same reason why all HSR service should enter the corridor at Redwood City from Altamont Pass, rather than gumming up the entire length of the peninsula corridor.  The blended system would be easier to plan, cheaper to build, and provide far better service to passengers.

The Caltrain/HSR Blended Grade Crossing Traffic Analysis was published on the Caltrain website and concluded the following:

Additional analysis is necessary. However, before doing so, speculation should be minimized. A better understanding of the schedule and decision on passing tracks should be advanced before further traffic analysis is conducted.

That's a fancy way of saying that grade crossing conditions will depend heavily on what the eventual timetable will be, so that a timetable needs to be developed first.  Perhaps Caltrain will some day see that everything revolves around timetable planning.  The timetable is where it starts from, to determine infrastructure needs and grade crossing impacts, and also where it all ends up, to quantify service quality improvements for each community along the peninsula corridor.  Timetable planning is precisely where Caltrain is not spending a lot of effort, because they think they already know the answer, in the form of a general class of "peak period skip stop zone express" timetables described in the 2012 Caltrain/HSR Blended Operations Analysis (see page 34).  There's a lot of work left to be done in this area, starting with undoing Caltrain's mistaken fixation on "peak period skip stop zone express" timetables.  As far as this grade crossing traffic analysis is concerned, Caltrain put the cart before the horse.

The CBOSS train control project chugged along, with a couple of recent puff pieces in the local newspapers. This project is where the lion's share of Caltrain's capital budget is going these days:

Design work is about 50 percent complete, said Karen Antion, who is essentially the boss of CBOSS and a highly-experienced and highly-paid consultant. [...] The design of CBOSS should be complete by September, Antion said.

Is this the same design work that leads up to the Critical Design Reviews that were supposed to have been completed last March?  If so, CBOSS is now a year behind the original plan, and that's before the really hard task of integrating and testing a system that is so proudly proclaimed to be "unique to Caltrain."  It sure is comforting to hear that we've got such a wide spectrum of on-call consultants to get us out of any trouble.

Meanwhile, staff has already softened up the board for the impending Option 2 (Phase 3) contract, to be rubber-stamped at the August board meeting.  The status of key milestones in the scope of Option 1 (Phase 2) is artfully avoided.  This $86.5 million contract is the "final" increment of funding for CBOSS, before the need for an Option 3 (Phase 4) makes itself known, most likely in late 2014.

Remember SuperVia, of Rio de Janeiro?  They are already well into testing.  Their consultants must be absolutely stellar.

The San Carlos Transit Village project is inexorably nearing approval later this month despite strong (and legitimate) NIMBY opposition.  Apparently piqued by claims that SamTrans is sabotaging the modernization of the peninsula rail corridor by selling off land that will be needed for new passing tracks, both SamTrans and Caltrain have issued letters disavowing any ill effect to the rail corridor or to the adjacent Old County Road, essentially by claiming that nothing has been decided yet:

The blended system is undefined at this time and we cannot predict its impact

This is a strange claim to make, given that all the analysis reports commissioned by Caltrain in the last couple of years point towards additional passing tracks (the "midline overtake") being built right through San Carlos and the new Transit Village.

The San Bruno grade separation opened to train traffic, even if the project is far from complete.  Trains now use the tracks built atop a mechanically stabilized earth embankment (basically walls held together by the weight of the dirt fill in between) that could be representative of future grade separations elsewhere on the corridor.

The Thruth About Tejon

A quick programming note...

There's an explanation for the long silence in these pages.  I've been busy writing about an issue that is outside the scope of HSR and Caltrain on the peninsula.  See my post about the southern California mountain crossing, over on the California High-Speed Rail Blog.

Regular programming will return soon.