The Canyonero of Signals

The San Bruno grade separation, a $155 million project that does nothing for the average Caltrain rider, is nearing completion.  If you wondered where some of that money went, here you go.

The Canyonero of signals is surely this brawny Made in U.S.A. signal gantry mounted on top of the San Bruno grade separation.  The gantry (probably a standard two-track gantry, to save money!) was too wide to be mounted in this location, so two cantilevered concrete platforms, seismically worthy, were built on each side to support the gantry and keep out any terrorists.  [UPDATE: check out the engineering drawing!]  If that wasn't enough, this signal gantry needed its signal house (probably a standard 8'x8' signal house, to save money!) perched on top of the opulent platform as well, with classy electrical conduits slung underneath and a dedicated ADA-compliant staircase allowing maintenance personnel ready access.  Maybe they were trying to save some parking spaces by suspending everything, but the entire area had to be fenced in for security.

East side, showing cantilever platform

West side, with signal house on cantilever platform

Under-hanging conduits connecting the signal heads to the relay shelter

If you asked the engineers who designed this, they could no doubt bend your ear about why it ended up this way and how numerous standards and requirements conspired to force exactly this solution.  That doesn't remove the simple fact that it's wrong.  It isn't simple, elegant, efficient, or thrifty; it fails to satisfy basic ideals that all engineering has aspired to since time immemorial.  The ridiculous, over-wrought outcome of rigid paint-by-numbers adherence to prescriptive requirements and standards would be comical if it weren't such a waste of the scarce taxpayer dollars available for rail projects.  (Or even that sub-category of rail projects solely benefiting automobile traffic flow.)  It's a basic signal gantry, for crying out loud.

Oh, and the new speed limit at the San Bruno curve, the #1 worst curve on the entire peninsula?  65 mph, up from 60 mph before.  It could have been 100 mph if this project had been conceived intelligently.

The concrete has been poured, and this installation shall now and forever stand as a monument to our Transit Industrial Complex, as it embarks on far more challenging endeavors such as electrification, level boarding, the downtown extension, and maybe some day high-speed rail.  The symbolism is hard to avoid.

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.

Grade Separation: The Decadal View

For the last few years of debate around the issue of high-speed rail, grade separating the peninsula rail corridor was often cast as an all-or-nothing proposition.  This extremist view clouded two important facts: first, the corridor is already mostly grade-separated (in 2013, only 40 road crossings out of 104 between San Francisco and San Jose will remain at grade); and second, grade separation is a slow and inexorable process that takes place over many decades.

If we assume the next several decades will be like the last several decades, we can take an educated guess about how and in what order grade separations will be built.  The criteria for prioritizing each project could be:

• creating long, uninterrupted stretches of grade separated right of way to enable higher train speeds without compromising safety
• creating a four-track mid-line overtake facility to increase the capacity of the corridor, to support initial HSR service
• separating crossings that rank highest in the CPUC's Section 190 Grade Separation Priority List
• delaying the most expensive and politically costly projects until last

Phase I is simply the completion of the San Bruno grade separation in 2013.  The San Mateo / San Bruno grade crossing being replaced was once rated #7 statewide on the CPUC's priority list.

Phase I: San Bruno Grade Separation

Phase II consists of four projects in San Mateo County, opening up two long stretches free of crossings by the early 2020s, including 14.8 miles free of crossings north of Burlingame, and 6.5 miles south of San Mateo.  This enables the future construction of the "short" mid-line overtake envisioned in Caltrain's corridor capacity analysis, and leaves only a few dense clusters of crossings within San Mateo County.  The new grade separations, in order of priority, are:

1. 25th Ave in San Mateo, the only grade crossing that remains between San Mateo and Redwood City.  Along with new grade separations already planned at 28th and 31st, this project enables the future 4-track mid-line overtake.
2. Broadway in Burlingame, an extremely congested crossing that has been slated for grade separation since the 1970s.  It rates #11 statewide on the latest CPUC priority list.
3. Linden Ave in South San Francisco, originally planned as part of the San Bruno project, but dropped from the final design in 2007.  Grade-separation at Linden is accompanied by the closure of Scott St, which becomes a pedestrian tunnel.
4. Center Street in Millbrae, a grade separation that will require a U-shaped elevated ramp due to the nearby BART subway tunnel box.  Such are the consequences of bad planning.

Each of these projects is independent and can be negotiated on a case-by-case basis with the four affected cities.  Starting in San Mateo County allows at least another decade for the Pacheco vs. Altamont debate to run its due course, legally and politically; these four projects are useful either way.

Phase II: San Mateo County Grade Separations

Phase III occurs mostly in Santa Clara County, creating a new stretch free of grade crossings from the southern half of Palo Alto all the way to San Jose in the late 2020s, assuming the routing of HSR over Pacheco survives as currently planned.  The last two grade crossings in San Francisco are also eliminated as part of the downtown extension project.  This phase includes the following six discrete projects:

1. Mary Ave in Sunnyvale, the corridor's busiest grade crossing in this county, with more than 25,000 daily vehicles
2. Sunnyvale Ave
3. Rengstorff in Mountain View, with about 18,000 daily vehicles
4. Castro in Mountain View, with about 9,000 daily vehicles
5. Charleston and East Meadow in Palo Alto, with a combined ~30,000 daily vehicles plus numerous pedestrians and bicyclists
6. 16th and Common in San Francisco, as part of the DTX project

Together, these six projects create a new 16-mile stretch of track that is entirely free of grade crossings.  The corridor is now left with just three dense clusters of grade crossings, in San Mateo / Burlingame, Redwood City, and PAMPA (Palo Alto - Menlo Park - Atherton), highlighted in orange in the figure below.  Note that these three dense clusters contain 27 crossings, and that to get this far, only 12 existing crossings were newly separated.

Phase III: Santa Clara County Grade Separations

Phase IV is the Great Redwood City Grade Separation.  This project, potentially for the early 2030s, would prolong the four-track mid-line overtake by three miles, by removing six grade crossings in downtown Redwood City.  Removing this cluster first makes sense from the standpoint of increased corridor capacity, the lowest number of new structures, the short mileage, and the entire project being politically simplified by virtue of its containment within Redwood City limits.

Phase V is the Great San Mateo / Burlingame Grade Separation.   This is a tougher project because it involves some of the most highly constricted portions of the corridor.  It also involves political and technical coordination between two neighboring cities, adding an additional challenge.  The sheer quantity of crossings (13 grade crossings + 4 obsolete grade separations within 2.4 miles) is also a complicating factor.

Phase VI is the Great PAMPA Grade Separation.  This project is left for last because it lies in the most expensive real estate on the corridor, involves coordination between three different cities, and is liable to cause the fiercest political and legal backlash anywhere on the peninsula.  Delaying it until last, perhaps into the late 2030s, allows the customarily long planning process to run its course without undue haste in all three affected communities.

We didn't arrive at today's state of grade separation (more than half) overnight.  It resulted from a slow and steady process that began in earnest in the 1940s.  The future is likely to be similar, and the peninsula rail corridor can reach a far improved state by separating just 12 more crossings over the next couple of decades, as described in Phases II and III.  This dozen should be prioritized for construction, before any of the crossings in the remaining dense clusters are touched.

San Bruno Out To Bid

Caltrain's San Bruno grade separation project is out to bid as of March 11th. The final engineering drawings reveal the HSR-hostile curve radius of 2387 feet, good for 75 mph (see details at right). While Caltrain has been exercising eminent domain in preparation for construction, they never seemed interested in acquiring the run-down houses on the inside of the curve to straighten out what is, has been, and will now forever be the #1 worst curve on the peninsula.

Caltrain officials continue to spread the falsehood that the curve is HSR-ready and that the design speed is 90 mph. Unfortunately, at an aggressive total cant of 12 inches (6 inches superelevation plus 6 inches unbalance) this curve will forever be restricted to a bit over 80 mph. Total cant would approach a drink-spilling 15 inches to run a train through the inside curve at 90 mph, something the FRA will never allow.

HSR trip time penalty: about 25 seconds, or 1/4 percent of the entire SF - LA run.

That may not sound like much, but when you consider that trip time is the foundation of high-speed rail, and that the next second saved always costs more than the last second saved, San Bruno is a terrible way to start off on the HSR path. Those 25 forsaken seconds will have to be recovered elsewhere, likely at far greater incremental cost than just doing San Bruno right with a 100 mph curve.

(we'll say nothing of the doomed-to-do-over 8 inch station platforms to be constructed right in the path of the future HSR alignment... that's just the cherry on this cake!)

San Bruno Done Wrong

[Update 9/10] The city of San Bruno has now coughed up $350k to grease the rails for this project.

[Original Post] There are new signs that Caltrain's San Bruno grade separation project is now on the fast track to construction. The project appeared in the MTC's recent Peninsula Corridor Investment Strategy as a top candidate for a slice of federal high speed rail stimulus funding, and is now also slated to receive $30 million in Proposition 1B state funding. Like the stimulus money, this new source of construction funds comes with strings attached: Caltrain and the city of San Bruno must award the construction contract by July 2010, effectively in the blink of an eye for such a big construction project.

A recent presentation to the San Bruno city council reveals that the project is the same old design that Caltrain engineered with BkF nearly a decade ago, a design that wasn't half bad for commuter rail. That was then; with high speed rail in the mix, the requirements have now changed--but the design (since taken over by HNTB) has not. As proposed, the San Bruno grade separation is fundamentally ill-suited to high speed rail and mixed corridor operations. Evidently, nobody sees anything wrong with this.

"It is very hard to get a man to see the truth of a proposition when his salary depends on it being false." -- Mark Twain

The proposition, in this case, is that the San Bruno grade separation project is a poorly conceived design that will significantly set back HSR and Caltrain service, and is therefore a tragic waste of taxpayer money. Because of the millions of dollars involved, this proposition is likely to fall on deaf ears in our local transportation industrial complex.

Ready, Fire, Aim!

In the headlong rush to shovel readiness, key shortcomings are being ignored.

• The San Bruno grade separation fails to straighten the worst curve on the entire peninsula corridor. This is low-hanging fruit, which if not picked will cripple high speed rail trip times for generations to come. If there is only one place on the entire peninsula corridor where a small amount of eminent domain taking makes sense, this is it.
  
  
• The San Bruno grade separation is designed with outside platforms, which means that Caltrain is essentially shooting itself in the foot with regard to operational flexibility. As far as commuter service concerned, an island platform would be far superior when HSR is added to the corridor.
  
  
• The San Bruno grade separation is being built in two phases, first as a commuter-only two-track station, with later demolition required to build the second pair of tracks for HSR. That's doing it twice, rather than doing it right.

Penny Wise, Pound Foolish

$30 million (a small portion of which is featured in the opening photo by Tracy O) may sound like a lot, especially to a cash-starved public transit agency, but in the context of rebuilding the peninsula corridor for mixed Caltrain / HSR operations, it is but a drop in the bucket. The overall budget for the peninsula is well over $5,000 million, or nearly 200 times as much. Caltrain's outdated vision for San Bruno is not worth compromising the key corridor design decisions (curve speeds, express track configuration, station layout) that must be carefully weighed against the respective needs of Caltrain commuter service and long-distance high speed rail service.

Unless the key design decisions that impact service are not being weighed at all?

Caltrain, San Bruno and the CHSRA should slow down, take a deep breath, and DO IT RIGHT, even if that means turning down some funding. San Bruno can wait a few years, now that its dangerous rail crossings have received interim safety improvements.

The Peninsula Corridor Investment Strategy

The Metropolitan Transportation Commission (MTC) recently published a Peninsula Corridor Investment Strategy, shepherding together various competing interests (CHSRA, TJPA, Caltrain, SFCTA, San Jose, VTA) to ensure that the Bay Area presents a unified front in its pursuit of a $1.8 billion slice of the $8.0 billion of ARRA stimulus funding available for high speed rail.

The MTC report contains a few surprises. But first, here are the projects contained in the $1.8 billion peninsula funding request. Also refer to pie chart at right.

• $400M for the San Francisco Transbay Transit Center "train box"
  
• $516M for Caltrain electrification
  
• $230M for Positive Train Control (automatic signal enforcement) for the peninsula (*)
  
• $212M for Caltrain's San Bruno grade separation project
  
• $205M for a newly revealed TTC train box "Rail Platform Extension" (*)
  
• $149M for reconfiguration / HSR modernization of Caltrain's Diridon station in SJ (*)
  
• $98M for reconfiguration / HSR modernization of Caltrain's 4th & King station in SF (*)
  
• $52M for DTX (SF downtown rail extension) design (*)
  

Projects with an asterisk (*) are funded nearly entirely out of the stimulus. Those without an asterisk have additional sources of funding already allocated.

A Two-Phase Approach

ARRA stimulus funds are targeted for so-called "shovel-ready" projects that can create short term jobs. That puts the California High Speed Rail Authority's San Francisco to San Jose HST project out of the running; the high speed rail project on the peninsula is in the early stages of an environmental clearance process that promises to be highly contentious, to be completed in 2011 at the earliest. While design work is already well underway, the controversial quadruple tracking, the numerous grade separations, and the wholesale reconstruction of nearly every Caltrain station planned by the CHSRA are not even close to shovel-ready.

That evidently pushed the MTC to split the construction of high speed rail on the peninsula into two phases. The first phase (as listed above) consists of a patchwork of projects that were already in the planning / environmental clearance pipeline before Proposition 1A was passed and HSR became a realistic prospect. It's definitely a pragmatic approach, with some caveats discussed below.

A Sudden Caltrain Bounty

Caltrain, with its appointed three-county board of directors, has historically held very little clout in getting its major capital improvements prioritized by the MTC. As recently as a few months ago, the MTC re-allocated $91M of Dumbarton rail (a.k.a. Caltrain) funding over to BART. Caltrain's biggest capital improvement project, planned for decades but with an ever-receding construction start date, is the electrification of the peninsula corridor with 25 kV overhead wires to provide quicker and more modern service. (artist's concept at left).

In the Peninsula Corridor Investment Strategy, Caltrain projects are suddenly front and center, thanks to their relatively advanced state of shovel-readiness and some new-found political support. This is a welcome change from the usual BART über alles funding strategy.

Caltrain electrification was always considered an unwelcome fly in the BART-around-the-Bay ointment. Now that billions of HSR funding have materialized, the Bay Area transportation-industrial complex is seemingly more attracted to HSR than to BART, if that is even possible. This changes everything: far from being an impediment to BART, electrification is now a "foot in the door" for bringing high speed trains into San Francisco and undertaking some very juicy construction projects during Phase 2--including several billion dollars of grade separations.

For thousands of Caltrain commuters, it should be welcome news that electrification has gone from problem to solution. Nevertheless, one question comes immediately to mind...

Is The Cart Before The Horse?

Does it make sense to electrify Caltrain in Phase 1, only to rebuild the corridor once the HSR project is environmentally approved and construction begins for Phase 2?

Pros:

• Commuter improvements are not beholden to HSR Phase 2 schedule, which may be delayed pending environmental review and inevitable litigation
  
• Electifying in Phase 1 conveniently coincides with the timing of Caltrain's unavoidable need to replace their obsolete train fleet
  
• Electrical substations and other lineside equipment can remain as-is for Phase 2 (Caltrain's planned 25 kV system is world-standard and fully compatible with HSR)
  
• The overhead contact system (basically anything above the rails) is made of modular components, easily reused or reconfigured
• Electrifying in Phase 1 allows testing / commissioning and possibly even limited high speed train service prior to Phase 2 completion
  

Cons:

• Building temporary "shoo-fly" detour tracks during grade separation construction becomes marginally more complicated
  
• Since vertical and horizontal alignment of tracks will be altered in many places, pole footings will need to be reconfigured. This is probably just a footnote on the demolition orders, considering that nearly all existing Caltrain station platforms and most existing grade separations will be entirely rebuilt in Phase 2.
  

Not that any of this matters, since the agenda is more political than technical--but thankfully, the pros do seem to outweigh the cons on a purely technical basis.

Bang for Buck: High

Go-Go Gadget Train Box!

A few months ago, the Transbay Joint Powers Authority (the agency charged with building the new Transbay Transit Center) got into a tiff with the CHSRA over the adequacy of their train platform layout. Entrenched in conflicting positions, the TJPA designed a 150-meter radius curve (extremely and impractically sharp) into one end of their platforms, while the CHSRA adamantly insisted on perfectly straight 400-meter platforms. We didn't hear any more about this little mind-the-gap issue, until now.

The Peninsula Corridor Investment Strategy asks $205 million for a "Rail Platform Extension" which would extend the train box north-eastward from Beale St. to Main St., as shown in the figure at right, to enable the sacrosanct straight platforms.

Sadly, it's another design by committee. The CHSRA's straight platforms are not a valid technical requirement. The underlying requirement concerns the admissible gap between the platform and a train's doors... and any reasonable value of that gap will still allow for some amount of curvature, however slight. For example, a 1 km radius will produce an additional gap of 5 cm (2 inches) at most. As if proof were necessary, high speed trains stop at curved platforms in nearly every county that has them.

Extending the train box has enormous potential for the Transbay Transit Center, for other reasons than making the platforms perfectly straight. That potential would be fully exploited by a proper design of the train box, to be discussed another time. And why does a 250-foot extension cost another 50% more than the basic train box?

Bang for Buck: Medium (for reasons unrelated to platform curvature)

San Bruno Grade Separation

A worthy project provided they do it right and straighten the darn curve.

Bang for Buck:
Zero (if built as Caltrain designed it)
Medium (if they straighten the curve)
High (if they straighten the curve and build an island platform)

Fourth and King Terminal

Caltrain had unfunded plans to modernize and expand the 4th & King terminal in San Francisco, as part of their Project 2025 plan. They even have a track layout in mind. For this, a design totally removed from system-level optimization of San Francisco rail operations, they are asking $98 million.

If somebody cared enough to configure the Transbay Terminal correctly, perhaps the 4th & King station wouldn't need to make up for Transbay's glaring lack of capacity.

Bang for Buck: Low (if only they fixed Transbay instead!)

Positive Train Control

The Investment Strategy calls for fully $230 million (!) to implement positive train control on the peninsula corridor. While PTC would finally bring the corridor out of the 19th century, why is Caltrain in the driver's seat to define the system for all of California? And why are they re-inventing the wheel by "defining the requirements" for a "new signal system" when this technology is a solved problem, sold as a commodity off-the-shelf item by countries that already have modern railways? Buy a fully debugged ETCS Level 2 system from your choice of several established vendors, and be done with it already! This is sure to become another disastrous R&D project.

Bang for Buck: Low

Diridon Pan-Galactic

San Jose's naked ambition to become the Grand Central of the West is on full display, with a $150 million grab to build a new station whose grandiose architectural configuration is rooted more firmly in a civic inferiority complex than any realistic transportation need.

Bang for Buck: Very Low

In closing, can we really expect $1.8 billion dollars (more than 20% of the nationwide high speed rail stimulus) to land in the Bay Area? Probably not. Whatever the Bay Area may score in Washington, the Peninsula Corridor Investment Strategy reveals a great deal about the region's evolving funding priorities.

San Bruno Done Right

As previously noted in Focus on: San Bruno, Caltrain has already spent $10 million on plans to rebuild the San Bruno station with new grade separations for downtown streets. These detailed plans (refer to plan views and cross-sections) were completed several years ago, and are now dormant for lack of construction funding. The recent economic downturn is creating renewed interest in the San Bruno project, because it is technically "shovel ready" with environmental clearances, community buy-in, and preliminary design work completed. The California High Speed Rail Authority, in its drive to carve out a slice of the $8 billion of high speed rail stimulus funding, has identified the San Bruno project as one of the few "shovel ready" items it can fund before the expiration of stimulus funding in 2012. The project, estimated to cost $300 million, is likely to appear on the list to be discussed at its May board meeting. San Bruno may not know it yet, but it is definitely on the fast track.

Quick Links (discussed extensively below)

• San Bruno Done Right dimensioned plan view PDF (224kb)
• San Bruno Done Right 3D model (1.1mb) for Google Earth

Not So Fast

Caltrain's design for the San Bruno station was conceived for commuter rail operations, with two extra tracks added ostensibly for HSR but equally useful for Baby Bullet express service. Whatever they may claim, Caltrain's old design is not compatible with high speed rail and threatens to lock in two disastrous design decisions before the conceptual engineering for HSR is complete.

First, the exceedingly sharp 60 mph curve at San Bruno would delay each HSR service by about 40 seconds; this curve was previously singled out as the worst curve for HSR on the peninsula corridor. This curve is so sharp that it needs flange greasers (shown at left) to squirt lubricant on train wheels, to mitigate wear and noise. Nevertheless, Caltrain officials have expressed ambivalence about straightening San Bruno curve, believing that the few seconds it would save are insignificant. A few seconds here, a few seconds there, and pretty soon it ain't high speed rail anymore... But why should they care, indeed? Straightening the curve for 100+ mph provides zero operational benefit to Caltrain. Any why would the CHSRA care, as they are tripping all over themselves to get something--anything--funded, and shovels turning dirt? Unfortunately, jerking a high speed train through a sharp 60 mph curve is very energy intensive and environmentally wasteful, and fundamentally at odds with modern train control software which seeks to minimize energy consumption. Assuming a realistic, environmentally appropriate, energy conservative speed profile, the San Bruno curve threatens to cost HSR far more than the 40 seconds lost in a lead-foot acceleration scenario.

Second, Caltrain's new station design at San Bruno puts the platforms on the outside, with the express tracks in the center. As was discussed in Slow Traffic Keep Left, this is probably not the best arrangement for a corridor shared with HSR, mainly because Caltrain service disruptions can propagate to HSR and disrupt service state-wide. Where to put the express tracks, and thus where to place Caltrain station platforms, is one of the most fundamental design decisions to be made on the peninsula, and it should be decided by a rigorous trade study. Such a momentous, corridor-wide decision should not default to five-year-old plans drawn up outside the high speed rail project.

San Bruno Done Right

Since a picture is worth a thousand words, a 3D model may be worth a thousand pictures. Here is the future San Bruno station and grade separation done right: with the curve straightened out for 100 mph operation, and a central island platform for Caltrain.

Download Google Earth model, enable the Terrain checkbox, and click on Tour. Make sure to fully explore the details of the station area, including stairways and platform canopy. (The necessary viewer, Google Earth, is free and easy to install.) At the new San Bruno,

• All pedestrian access paths lead to the correct platform.
  
  
• High speed trains, running on the outside tracks furthest away from the platform, save at least 40 seconds by avoiding the need to slow down for the sharp curve. That doesn't sound like much, but it's nearly half a percent of the entire express run from San Francisco to Los Angeles. Savings like this are too good to pass up.
  
  
• A continuous viaduct can be built across both San Bruno and San Mateo avenues, resulting in easy pedestrian access from anywhere in the vicinity of the station.
  
  
• The changes affect only the station area and adjacent curve. The remaining grade separations are identical to those proposed by Caltrain.

To be fair, this San Bruno design does have a few drawbacks. Straightening the curve requires taking a few residential properties on Montgomery Ave. by eminent domain--politically not very savory, considering this will likely be one of the first HSR construction sites on the peninsula. Nevertheless, such takings are kept to an absolute minimum by careful design of the curve, and amount to a tiny fraction of the project's $300 million price tag. The area allocated to station parking is also reduced somewhat, although an equivalent amount of parking could be recovered on the west side of the tracks.

For the track geometry junkies out there:

• The vertical track profile is similar to Caltrain's (see Appendix B page 4).
  
  
• The new horizontal alignment (see dimensioned plan view PDF) features a 1200 m (3900 ft) radius curve, good for 109 mph at 12 inch total equivalent cant or 100 mph at 10 inches.
  
  
• The 210 m (700 ft) long by 9 m (30 ft) wide platform is very slightly tapered to minimize the area consumed by track slews at each end of the platform; the radius of the southbound platform face is 6000 m (20,000 ft) and produces a less than 1 cm (3/8 inch) ADA-friendly platform gap, with a benign, ADA-friendly 25 mm (1 inch) superelevation, as demonstrated by the Bombardier cars placed in the 3D model.
  
  
• It is likely that all four tracks can fit under the I-380 viaduct without moving any support columns. Even if this were not feasible, and supposing that it became necessary to relocate one row of six columns, the CHSRA has already demonstrated a willingness to move freeway supports in their design for the north end of Tunnel #2 under I-280 in San Francisco. If it makes sense there, it makes far more sense in San Bruno.
  
  
• In recognition of the tight clearances under I-380, accurate Bloss spiral transition curves are shown. The tracks and station foundations do not interfere with existing BART tunnel, and the curve is configured so as to fit between the I-380 support columns while minimizing excursions from the existing right of way boundaries. These improvements are likely feasible without major re-engineering of adjacent civil structures.

On the whole, this proposed configuration would be a highly effective update of Caltrain's plans for San Bruno, making them fully compatible with High Speed Rail. Can we hope San Bruno will be done right?

Many thanks to Richard Mlynarik for his 3D modeling skills and advice on track geometry.

The Top 10 Worst Curves

The peninsula corridor was laid out in the mid 19th and early 20th centuries, for train speeds of that period. It is the oldest passenger line west of the Mississippi. Needless to say, rail technology has progressed enormously in the last 100 years. The California High Speed Rail Authority is now planning to run trains on the peninsula at a top speed of about 125 mph. Sounds great, but what about all the curves? (Bayshore curve photo by Michael Patrick)

Minimum Curve Radius

To allow HSR operation at 125 mph, just how wide does a curve need to be? This is an elementary calculation of railway engineering, and is determined by safety and passenger comfort. Without going into details, speed can be increased in a curve by banking the track into the turn, like a turning airplane or a freeway exit ramp. The outside rail can be canted or super-elevated a maximum of 7 inches (178 mm) higher than the inside rail. Trains can go even a bit faster than the speed that balances this banking, causing passengers to feel a sideways push to the outside of the curve. The technical term for this is cant deficiency, and under current FRA regulations it is limited to 3 inches. Within those limits (7 inches cant + 3 inches cant deficiency), physics dictates the following curve radii:

Speed	Minimum Radius	(Recommended Radius)
160 km/h (100 mph)	1200 m (4000 ft)	1800 m (5900 ft)
200 km/h (125 mph)	1900 m (6300 ft)	2800 m (9200 ft)
215 km/h (135 mph)	2200 m (7300 ft)	3200 m (10500 ft)

The recommended radius is preferred, in the absence of trackside constraints such as houses and roads, to keep passengers comfortable and reduce wear and tear on the trains and the track. Wherever curve clearances are constrained (i.e. pretty much anywhere on the peninsula), the minimum radius becomes the quantity of interest.

The Cost of Slowing Down

Slowing down from 125 mph to take a curve, and accelerating back up to 125 mph costs several seconds of travel time, compared to an uninterrupted run at 125 mph. It's just a few seconds, but if every curve eats a few seconds out of the schedule, pretty soon HSR starts losing its "high speed." So exactly how many seconds are too many? Maybe the answer lies in the cost of a second. If you assume:

• HSR annual ridership will be 60M passengers / year (considerably less than the CHSRA's estimate)
• About one third of all HSR passenger trips will include the peninsula segment
  
• The average passenger (leisure and business) values their time at $12/hour (an approximate value based on time value studies)
  
• The cost of straightening a curve is amortized over 15 years of operation (the continuing benefit beyond 15 years is free)
  

Then each second of delay costs about $1 million of lost time to HSR passengers, and could be worth about $1 million in construction costs to remediate. That does not include the ancillary benefit to Caltrain Baby Bullet passengers. One can take issue with the exact assumptions and accounting methods, but the point of this exercise is to gain a very rough order of magnitude understanding for the cost of a second: on the order of a $1 million.

Using a typical deceleration / acceleration rate of 0.5 m/s^2, the cost of temporarily slowing down for a typical curve from a cruise speed of 125 mph goes as the square of the speed difference:

Curve Speed (mph)	Time Penalty (s)	Delay Cost
115	3	$3M
105	7	$7M
95	13	$13M
85	21	$21M
75	31	$31M
65	43	$43M

The square relationship means that it's not necessary to straighten curves all the way up to 125 mph. Arbitrarily setting our threshold of diminishing returns at 5 seconds of penalty, 110 mph curves can be considered "good enough" unless they can be straightened to 125 mph within the existing right of way, essentially for free. The reconstruction of any curve below 110 mph should be weighed against the dollar cost of time lost.

While this author is not versed in the fine art of estimating construction costs, we now have enough information to at least prioritize the worst curves where something should be done, short of deciding which ones are actually cost-effective to rebuild.

Existing Curves on the Peninsula

All major sub-125 mph curves in the Caltrain corridor from San Francisco to San Jose are shown in the chart below. Milepost is plotted along the bottom, and the curve's maximum speed is plotted on the vertical axis. The maximum speed is derived from the curve radius by assuming the aforementioned 10 inches of equivalent cant, except for reverse curves where different constraints apply. (Note, these speeds are not possible today; the maximum cant on Caltrain is 5 inches to accommodate freight trains, and the signaling system allows only 79 mph.)

Click for Larger View. First, there are quite a few curves that interfere with a 125 mph speed limit, as indicated by the blue dotted line.

• Several curves fall above the 110 mph "good enough" threshold, indicated by the green dotted line, although they should still be candidates for realignment if they are easy to fix. Recall these speeds are absolute maximum speeds, with 3 inches of cant deficiency (passenger discomfort).
  
• Some curves are very tight, but would be impossibly expensive to straighten; an example is the Sierra Point curve, which runs around the base of San Bruno mountain. There are other sharp curves in the San Francisco and San Jose terminal areas that fall into this category.
  
• One curve will be avoided entirely by HSR: the infamous CEMOF double reverse curve in San Jose, where the most expensive way to avoid a curve is planned, namely a tunnel.

Leaving aside these "impossible" curves and the "good enough" curves, we can examine the remaining curves and construct a list of the worst curves for HSR on the peninsula.

The Top Ten Worst Curves

Here's a Google map, although it is much more accurate and instructive to view the KML file directly in Google Earth.


View Larger Map

#10 (Honorable Mention) CEMOF Double Reverse Curve - Milepost 46.5 - While the CHSRA plans a tunnel under this area, you really have to wonder what Caltrain was thinking when they dropped this turd on the approach to San Jose. That's why it gets an honorable mention.

#9 Belmont - San Carlos Reverse Curve - Milepost 22.4 - While we're adding another two tracks here, the incremental cost of straightening this curve to 125 mph ought to be near zero, since it can probably be done within the existing ROW. Savings: 10 seconds.

#8 San Antonio Curve (see curve detail map) - Milepost 34.3 - Great potential for straightening to 125 mph, again within the existing ROW. Savings: a couple of seconds, but it's free!

#7 Bowers Curve (see curve detail map) - Milepost 41.9 - Already OK for nearly 110 mph, but could use as much flattening as practical because of the proximity of Lawrence curve.

#6 Lawrence Curve (see curve detail map) - Milepost 40.6 - This shallow 100 mph curve can easily be straightened all the way up to 125 mph by purchasing a narrow strip of office parking lot (which Sunnyvale has plans to redevelop anyway). This is low-hanging fruit, well worth the 10 second savings.

#5 Hayward Park Curve (see curve detail map) - Milepost 18.8 - This curve was already straightened in the year 2000 by moving the rails by 20 ft. It might now support 95 mph. Would be better at 110 mph, saving about 10 seconds.

#4 Millbrae Curve (see curve detail map) - Milepost 13.9 - An unfortunate consequence of the last Quentin Kopp extravaganza, the BART airport extension. Challenge: BART tail tracks occupy the inside of this 90 mph curve. BART would have to give up one of three tail tracks to straighten for 100 - 110 mph operation. This ought to be feasible: two of the tail tracks were built in anticipation of a BART extension south of Millbrae, which no longer makes sense. Savings: about 15 seconds.

#3 Palo Alto Station - Milepost 30.1 - Already discussed in Focus on Palo Alto. While the existing curve radii are gentle, the problem at Palo Alto is a double reverse curve, which requires long spiral easements to reverse the curvature and prevents the speeds you might deduce from the radius alone. The southbound track is good for just under 90 mph. Challenge: reconfigure the Alma St. overpass; on the plus side, JPB already owns all the required land. Savings: about 25 seconds. A must-do, regardless of whether Palo Alto becomes an HSR station.

#2 Bayshore Curve (see curve detail map) - Milepost 5.1 - Just north of the Bayshore station at the mouth of Tunnel #4, this curve is a piece of cake to straighten to 125 mph, provided Bayshore station is redone. This will probably happen anyway to make room for the approaches to the planned new tunnel bores on each side of the existing tunnel. The new tunnel bores could even have curved ends. Savings: about 20 seconds. Cost of new platforms: $10M tops. Low hanging fruit, just waiting to be picked!

#1 Worst Curve: San Bruno Curve (see curve detail map) - Milepost 10.9 - previously discussed in the San Bruno article. This curve, currently 65 mph, should be straightened to 110 mph minimum. Savings: a whopping 40 seconds. Challenges: well-advanced plans by Caltrain for a new station, locking in the existing curvature; eminent domain for ~$5M worth of houses on the inside of the curve; six I-380 viaduct pillars would need to be moved. If this curve can be fixed even for $30-40M, JUST DO IT!

The total time saved from straightening these 10 curves is about 2 minutes, not including the savings from straightening the other 110 mph+ curves not listed here. These time savings add up to ~7% of the non-stop travel time between San Francisco and San Jose, expected to be around 30 minutes.

The CHSRA and its engineering contractors should not resign themselves to the existing curvature of the peninsula corridor. A rigorous study of curve remediation should be undertaken before the new track alignments are finalized.

Update - 02 Feb 09

It was brought to my attention that the CHSRA published in its considerable (if un-navigable) body of work a series of run simulations. This is what the pros do, instead of the back-of-the-envelope calculations detailed here. A sample San Jose to San Francisco run is detailed below. The train used in the simulation is a Siemens ICE 3. It does not stop in San Jose in this particular example. Total time from San Jose (running start) to San Francisco is a few seconds short of 30 minutes (1793 seconds, to be precise)

This simulation reveals a couple of interesting assumptions on the part of the CHSRA's analysts:

• Total cant is 12 inches (vs. 10 inches assumed in the calculations above) allowing 10% higher curve speeds. This is not outlandish: 12 inches is practiced today on the NEC.
  
• The Palo Alto and Bayshore curves are evidently straightened out, with a curved platform at Palo Alto
  
• None of the other bad curves appear to be straightened, as revealed by the three deep notches in the speed profile at Hayward Park, Millbrae and San Bruno.
• The train's throttle is used heavily, and the regenerative brake will certainly get a good workout. Whether this lead-footed driving style is realistic is open to discussion.
  

While these assumptions are self-consistent and do not violate any laws of physics, they are somewhat optimistic. This is another reason to straighten San Bruno curve: then you could do SF to SJ in 30 minutes with margin.

Focus on: San Bruno

San Bruno is the point of departure for the "Bayshore Cutoff" to San Francisco, built in the early 1900s by the Southern Pacific Railroad. The rail line to San Francisco originally went straight through San Bruno and detoured around the west side of San Bruno mountain, where BART runs today. The cutoff was built around the east side of the mountain, then through a series of tunnels, as a shortcut into San Francisco. This is the alignment used by Caltrain today and planned for HSR.

San Bruno Curve

One important consequence of this history is that San Bruno is left with one of the sharpest curves on the peninsula, where the cutoff formerly diverged from the old main line. The radius of the curve is 1800 feet (550 meters), giving it a maximum safe speed of about 70 mph (115 km/h). Caltrain has a speed limit of 60 mph at this location. Slowing down a high speed train from a peninsula cruise speed of 125 mph (200 km/h) to take the existing San Bruno curve would cost more than a minute, or over half a percent of the entire SF to LA running time. Considering how much investment is being made to shave seconds off run times for the entire system, a 1-minute penalty in San Bruno for a single curve should raise some red flags at the CHSRA.

Consider the "San Bruno Curve" a significant obstacle to HSR on the peninsula.

To run trains safely at 110 mph through the curve, it would have to be straightened to a radius of 1200 m. This is shown as a blue outline in the map to the right (see the Top Ten Worst Curves for more information on curves). Straightening the San Bruno curve for HSR is complicated by several factors:

• The houses along Montgomery Ave, on the inside of the curve, would likely have to be taken by eminent domain. According to zillow.com these houses are worth a combined $6 million, a relative drop in the bucket compared to the $4200 million to be spent on the peninsula alone. The tracks would also pass on the site of the former lumber yard on the inside of the curve, recently torn down.
  
• The viaduct for I-380 (named, irony of ironies, the Quentin L. Kopp freeway) crosses over the tracks at the north end of the curve, supported by a forest of beefy concrete pillars.
• Caltrain has planned a 4-track grade separation in this location (see below) that essentially preserves the existing sharp curve. (The radius was planned to increase slightly from 1800 ft to a still-tight 2000 ft, staying within the existing Caltrain right-of-way.) However ill-conceived, these planning errors have a sneaky way of perpetuating themselves, especially after the $10 million spent to date on engineering this project.

The next significant curve, 2.5 miles to the north, around the base of San Bruno mountain at Sierra Point, has a radius of about 2600 ft (800 m), giving it a maximum safe speed of about 85 mph (140 km/h). This curve cannot be straightened due to the local topography, but is sufficiently distant from San Bruno to allow trains to accelerate to 125 mph (200 km/h) by the time they reach San Bruno curve.

Grade Separations

San Bruno has grade crossings at Angus Ave, Scott St, and San Mateo and San Bruno Avenues. The latter is known as one of the most dangerous crossings on the peninsula, because San Mateo Ave crosses the tracks at an acute angle and the nearby curve limits visibility for trains, auto traffic and pedestrians.

Caltrain and the city of San Bruno have long-standing plans to grade-separate the crossings in San Bruno. These plans have been delayed several times due to funding issues, most recently until 2012. Caltrain has produced a detailed Grade Separation Study Report, from which the preliminary track layout is of particular interest. The city of San Bruno is developing a downtown and transit corridors plan that includes the Caltrain station area. The San Bruno Caltrain station would be rebuilt to the north of its current location with four tracks, elevated over the San Mateo Ave / San Bruno Ave crossings. The streets would be sunk to pass under the new station. The Scott St. crossing would be closed to auto traffic, with a pedestrian / bike underpass built instead. The proximity of the BART tunnel, which passes under the Caltrain tracks just south of San Mateo Ave, is a complicating factor discussed in the report.

With the passage of proposition 1A, Caltrain's plans for San Bruno should be thoroughly re-evaluated, regardless of the studies, $10 million of preliminary engineering, committees, public input and debate of the last several years. With high speed rail in the mix, the requirements have changed, and the biggest problem with the existing plans is the San Bruno curve.

HSR Plans

The California High Speed Rail Authority's Bay Area EIR / EIS, Appendix D, shows the alignment through San Bruno as a 15-foot tall retained fill embankment with split grade separations (exactly as planned by Caltrain, except with four tracks all the way through town). The rails dip down briefly to grade level as they pass under the I-380 viaduct.

The CHSRA gives no indication of an intention to straighten San Bruno curve; their plans show the tracks following the existing Caltrain right-of-way.

San Bruno Done Right

Since a picture is worth a thousand words, a 3D model may be worth a thousand pictures. Here is the future San Bruno station and grade separation done right: with the curve straightened out for 100 mph operation, and a central island platform for Caltrain.

Download Google Earth model, enable the Terrain checkbox, and click on Tour. Make sure to fully explore the details of the station area, including stairways and platform canopy. (The necessary viewer, Google Earth, is free and easy to install.)

For more details on this proposed design for the San Bruno station, see San Bruno Done Right.

NOTE: This post will be updated continuously, as warranted by additional information or new events relating to San Bruno.