Caltrain Does the Right Thing: Nothing

For a few months after the passage of Proposition 1A in November 2008, it seemed as if Caltrain was conducting business as usual on its capital improvement program. They are finally showing signs of waking up to HSR and its implications for the numerous capital projects in their pipeline. (photo by PBO31)

In April, Caltrain placed the renovation of the South San Francisco station on hold. This $50 million project, fully funded and at the 90% design stage--the shovel doesn't get any readier--was shut down at the last minute over uncertainty in the plans for HSR and the future configuration of the Union Pacific freight yard located there. The project will resume when more is known about detailed HSR plans for the area, probably within the next two years.

Further south and for the better part of the decade, Caltrain had plans to replace century-old, seismically unsafe, low-clearance bridges just north of downtown San Mateo. These antiquated bridges, crossing over Poplar, Santa Inez, Monte Diablo and Tilton avenues, are so low that even the Google Street View camera car nearly crashed into one. The work on this $27 million project was to start this summer. Not only would these four bridges need to be rebuilt and expanded for HSR, but they are also located in an area where the future vertical alignment of the tracks is highly uncertain, depending on how the new tracks are routed through downtown San Mateo. A San Mateo resident rightly complained about the disconnect. Recently, Caltrain announced they were opting for a better approach, consisting of a basic seismic retrofit and continued maintenance to extend the lifetime of the bridges just long enough to find out what will happen with HSR.

As part of their announcement, they stated: Caltrain is assessing its extensive capital program to better coordinate with high-speed rail and to make certain that today’s investments are not deemed obsolete in the near future.

Better do it right than do it twice.

The Shape of Palo Alto

Several years ago, the city of Palo Alto commissioned a public art work entitled The Color of Palo Alto. At considerable expense ($75,000), artist Samuel Yates set out on a techno-artistic quest to determine the exact shade of Palo Alto. In a similar vein, and bearing in mind that artistic form is more than just color, we set out to determine the shape of Palo Alto.

Why does the shape matter? While the area around the tracks in Palo Alto is pretty flat, small variations in the terrain do have an effect on how the high speed rail project will be configured as it crosses through town. The vertical alignment of the tracks must not only conform to the surrounding grade, but it must be routed over or under every creek, road, pedestrian or bike crossing while conforming to acceleration limits imposed by passenger comfort as well as train stability and performance.

There have already been strong hints as to what shape this vertical alignment might take, as previously discussed in Focus on Palo Alto. As part of its program-level EIR/EIS, the California High Speed Rail Authority produced a set of maps of the Caltrain corridor that fueled a firestorm of controversy in Palo Alto, with residents worried that raised tracks would form a Berlin Wall and divide the city. While the CHSRA now professes to consider all vertical alignment options for its project-level EIR/EIS, ranging from tunnels to elevated tracks, there aren't that many feasible and affordable ways to design the vertical alignment of HSR tracks through Palo Alto-- and it turns out that the shape of Palo Alto can tell us a lot about what those are.

Working from Caltrain track survey data, here is the shape of Palo Alto, with the vertical scale greatly exaggerated: (click to expand)

 Note a few salient features:

• Palo Alto isn't as flat as you might think. Who knew that the University Ave station is nearly 40 feet higher than the California Ave station?
  
• There are only four grade crossings in all of Palo Alto
  
• Including overpasses, underpasses and grade crossings, there are only nine places where pedestrians and bikes may cross the tracks in all of Palo Alto, and only seven places where roads cross the tracks
  
• The entire southern half of Palo Alto has only two places where pedestrians can cross the tracks, and both of them are very busy intersections.
  
• Four creeks cross under the tracks

As we consider various grade separation options, keep this in mind: while grade separations are a sine qua non condition for high speed rail, they could also become necessary in other non-HSR scenarios for the peninsula. For example, if Caltrain traffic increased to the point that grade crossing gates blocked rush hour traffic for too long (such as if HSR were to terminate in San Jose), or if BART were to connect Millbrae to Santa Clara, as originally planned in the 1960s. Grade separated tracks are by no means a unique requirement of HSR; they are likely to be required in Palo Alto within the next few decades, HSR or not.

Constraints on Vertical Alignment

Before evaluating various vertical track profile options in Palo Alto--especially if you're going to have a charrette--it's important to lay out a few simple, fundamental design rules that govern what you can and can't make the tracks do.

• The maximum grade (how steep the tracks can be) will be limited. High speed trains and electric commuter trains can easily climb 2% or 2.5% grades. Freight trains can't climb as steeply, and work best at 1% or maybe 1.5%.
  
• The radius of vertical curves (humps and sags) is constrained by maximum train speed. The vertical curves have to be gentle, unlike a roller coaster, to keep passengers comfortable and keep the train stable on the tracks as it crests over a hill. For 125 mph (200 km/h) operation, here are some typical track design standards:
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  

  Standard (at 125 mph)	Typical Radius	Minimum Radius
  European Technical Standard of Interoperability	14 km (9 mi)	10 km (6 mi)
  Germany	16 km (10 mi)	10 km (6 mi)
  Sweden	17 km (11 mi)	10 km (6 mi)

  
  
  
  Some standards do allow vertical curves with a radius barely over 6 km (4 mi), but only in exceptional circumstances. For the peninsula, using the minimum value of 10 km is probably a good starting point. This radius results in a vertical acceleration of 0.3 m/s2, or about 1/3 to 1/4 of the acceleration you might feel in a typical elevator--infinitely smoother than a roller coaster!
  
• To the extent possible, the vertical profile should avoid obstacles like creeks or existing overpasses and underpasses. While earthworks and concrete can be used to solve any such puzzle, the cost may be prohibitive.
  
• Where roads cross under the tracks, the vertical distance between the road surface and the top of the rails must be 20 feet to clear trucks and buses.
  
• Where tracks cross under roads, the vertical distance between the road surface and the top of the rails must be 30 feet to clear freight trains and overhead electrification.

The chart at right shows vertical track profiles for various combinations of these parameters. On the top half of the chart is a 20-foot elevated grade separation, with representative 1% or 2% grades and 10 km or 16 km vertical curve radius. On the bottom half is a 30-foot depressed grade separation (trench), with the same variations of grade and vertical curve radius. The chart gives you an idea of how long these structures need to be, based on how high (or deep) they are.

The Elevated Scenario

Elevating the tracks over Palo Alto's few remaining grade crossings is one scenario being proposed by the California High Speed Rail Authority, and is likely the cheapest.

Taking a step back: the only reason to elevate track that isn't already elevated is to lift the track over a road or pedestrian underpass, also known as a grade separation. The only place where that might happen is in the vicinity of grade crossings. Elevating the track anywhere else would serve no purpose and is not being contemplated.

Here's what the elevated scenario might look like:

• All vertical curve radii are 10 km (6 miles)
  
• At Charleston and Meadow, the tracks are raised by 7 feet and the road sunk by 13 feet. This embankment height was given in the CHSRA's program EIR/EIS maps.
  
• At Churchill, the tracks are raised by 15 feet, with 1.5% ramps. The CHSRA's program EIR/EIS maps showed the embankment starting well north of Palo Alto high school, presumably to avoid dipping down and back up; however, there is absolutely no harm in the hilly profile shown here. The only people who might dislike it are freight train operators, not HSR, because of slack action. Speaking of freight trains, this embankment could be made even shorter and steeper if it didn't have to be designed with the gentle grades required for freight trains.
  
• Alma (a.k.a. Palo Alto Ave) is lowered to cross under the existing track level.
  
• As evident in the diagram, any claims of a continuous 20-foot wall bisecting Palo Alto from one end to the other are exaggerated.

The Depressed Scenario

With respect to the outcry over the community impact of raised embankments, it's worth looking at another scenario... and it doesn't involve tunnels! While tunnels are often contemplated as the only possible alternative to embankments, it is possible to grade separate the Palo Alto crossings by depressing the tracks into trenches. Trenches are preferable to tunnels because they can be narrower and involve far less earth moving and concrete works... although still far more work than embankments.

Here is what the depressed scenario might look like:

• Note the length of the grade separations increases considerably, since they must dive a full 30 feet under street level and do so with gentle, train-friendly grades. The excavation itself would be even deeper, since the red curve is drawn at the top-of-rail level. Do note that accommodation of freight trains requires an extra 3 feet of vertical clearance.
  
• The trenches are shown with 1.5% ramps. Shallower ramps are not possible, since the natural grade is already nearly 1% near the Churchill crossing. Steeper ramps (2% or 2.5%) would be possible if it weren't for those freight trains. (Do we see a pattern yet with those pesky freight trains?)
  
• At Churchill, the northern ramp would not clear the existing Embarcadero grade separation. This complication might be solved by locally depressing Alma to match the track level, and rebuilding Embarcadero as a low overpass rather than an underpass--but as always, the devil is in the details.
  
• At Charleston and Meadow, the trench would encompass the existing location of the Barron and Adobe creeks. Grade-separating the creeks is possible, but it involves lots of concrete, pumps, and ongoing maintenance expenses.

While the depressed trench scenario introduces several challenges, they pale in comparison (and cost) compared to building a full-fledged tunnel.

The Big Picture

Despite the recent controversy in Palo Alto, the city is not even close to being the most difficult to build high speed rail. There are far more challenging puzzles up and down the peninsula, for example downtown San Mateo. Many of the same design principles apply to any location on the peninsula, and as time allows we'll start discussing some more of these puzzles. As for Palo Alto, the squeaky wheel gets the blog grease!

Lawsuit Preview

On August 8th, 2008, the cities of Atherton, Menlo Park, and a number of environmental and transit advocacy groups filed a lawsuit seeking to overturn the CHSRA's July 9th 2008 certification of their Bay Area to Central Valley program EIR/EIS, for failing to properly meet the requirements of CEQA environmental review regulations. This lawsuit, often characterized as an act of peninsula NIMBYism, will be heard later this month in Sacramento Superior Court.

10 interesting factoids about the lawsuit:

1. You can read all the legal briefs on the Sacramento Superior Court's document server. Select 2008 (the year the lawsuit was filed), and enter the case number 80000022, then hit the search button. This will dredge up all the latest documents; the original complaint is at the bottom of the list and is a must-read. The complaint outlines the basic claims made against the CHSRA's environmental review process, and describes the organizations who filed the lawsuit.
   
   
2. The lawsuit does not seek to stop the HSR project. It broadly challenges the thoroughness of the Environmental Impact Report, and specifically the selection of the Pacheco pass alignment over the Altamont Pass alignment, which was the subject of nearly a decade of contentious debate.
   
   
3. If the plaintiffs win and the EIR certification is overturned, the CHSRA would be required to re-open and amend their program EIR to address the deficiencies, and make a new alignment decision on the basis of the amended EIR before proceeding further.
   
   
4. A new EIR decision could very well re-affirm the Pacheco Pass alignment. It would not necessarily result in the selection of Altamont Pass.
   
   
5. The plaintiffs include grassroots transportation and rail advocacy groups who are strongly in favor of HSR, including TRANSDEF, Bay Rail Alliance, and the California Rail Foundation. This fact alone should explode the NIMBY stereotype that is often associated with this lawsuit. They want HSR but they want it done right, and their strong and united stance is noteworthy.
   
   
6. While the town of Atherton has a clear motive to keep HSR entirely outside its boundaries, it's not so cut and dried for co-plaintiff Menlo Park. Under an Altamont scenario, the HSR tracks would still traverse the city, but through some less affluent neighborhoods of east Menlo Park.
   
   
7. The city of Menlo Park's standing as a plaintiff was gravely undermined when it was ruled last March 27th that they did not properly submit their comments on the EIR. In an embarrassing breakdown of basic process, no records were kept of the city's submission of comments to the CHSRA, whether by fax or U.S. mail, and the CHSRA claimed never to have received them.
   
   
8. The Palo Alto city council emphatically and unanimously supported HSR until Proposition 1A passed in November. After severe backlash against the project in Palo Alto as details of the project became better known, the city council reversed itself and voted to join support the lawsuit. While it was too late to become a plaintiff, the city filed an amicus curiae brief on May 1st, which is now available on the court's document server (see item 1).
   
   
9. Any response from the CHSRA to Palo Alto's brief is required to be made by May 15th. UPDATE 5/18: the CHSRA's response to Palo Alto's amicus curiae brief is now available on the court's document server (see item 1).
   
   
10. The lawsuit is scheduled to be heard and likely decided by Sacramento Superior Court Judge Michael P. Kenny on May 29th.
    

Whatever the outcome, it should be interesting to watch. Make sure to have a plentiful stock of popcorn.

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.

Regulatory Vacuum

Preliminary design for the California High Speed Rail project is proceeding in the absence of key regulations from the California Public Utilities Commission (CPUC), the Federal Transit Administration (FTA), the Federal Railroad Administration (FRA), and numerous other agencies. While high speed rail is a very mature technology, it is still foreign and exotic in the United States, and our regulatory agencies do not yet have an effective or complete regulatory framework in place to direct the development of high speed track and trains. The regulatory vacuum is already causing some strange and potentially regrettable design decisions to be made, with negative consequences for the peninsula corridor.

Platform Heights

The side clearance dimensions around passenger rail platforms in California are regulated by the CPUC under General Order No. 26, originally issued in 1948, covering every relevant railroad situation from stock chutes to icing refrigerator cars. Where freight trains share tracks with passenger trains, as they do on the peninsula corridor, G.O. 26 limits passenger platforms to a height no more than 8 inches (203 mm) above the top of the rails (ATOR) to allow trainmen to ride on the side of freight cars without fear of getting clipped. Of course, none of these olde-tyme railroad practices are very relevant to 21st century rail technology.

Nevertheless, 8 inches is the maximum height of all existing Caltrain platforms. Taller platforms are allowed, but only beyond 7 feet 6 inches (2.3 m) from the track center line; in other words, taller platforms are only allowed if they do not come closer than about 3 feet from the side of a train. A lot of good that does for passengers! Combine G.O. 26 with ADA accessibility requirements, and you get a ghastly regulatory abortion called a "mini high platform" (see figure at right), to facilitate wheel chair boarding using a so-called "bridge plate" manually placed across the yawning moat between the high platform and the train. Mini-high platforms continue to sprout up and down the Caltrain line, most recently in Redwood City and Menlo Park, while elsewhere in the world, humans have discovered level boarding.

Of course, the regulatory rigors of accommodating freight trains are not anywhere on the CHSRA's radar screen, which is why they are planning for level boarding platforms regardless of where Caltrain eventually ends up--one can only hope, higher than eight inches. At stations to be served by both HSR and Caltrain, namely San Francisco, Millbrae, Redwood City or Palo Alto, and San Jose, it is quite possible that we will end up with different, incompatible platform heights with station tracks forever assigned to one or the other type of train. This runs counter to the most basic principles of interoperation, where the flexibility to assign any train to any platform (in a pinch) is paramount.

Moving beyond MOUs, who will bring about amended regulations to ensure that we have a common platform standard for HSR and Caltrain?

Who will make sure this standard allows the off-the-shelf procurement of new trains, without costly redesign? A hint: the most relevant platform heights are 22 inches (550 mm) and 30 inches (760 mm).

Why is Caltrain apparently not vigorously pursuing a waiver of G.O. 26?

High Voltage Electrification

Like platform clearances, overhead electrification of railroads is regulated by the CPUC. General Order 95 specifies the rules governing overhead electric line construction in California. Garden-variety 25 kilovolt overhead electrified railways do not exist in California, and G.O. 95 therefore does not allow them. That's right: 25 kV electrification is currently illegal in California. Caltrain has long-standing plans to electrify the peninsula corridor, and had been pursuing new regulations with the CPUC to cover 25 kV trains. More recently, the approach appears to have shifted towards obtaining a waiver from G.O. 95 instead.

Whatever happens, why is the heavy lifting for high speed rail being left to Caltrain? Moving beyond MOUs, where is the coordinated approach with HSR?

Safety and Train Control

Railroad safety in the United States is regulated by the FRA in a manner that places a premium on crash survival over crash avoidance. That's why we still have the 19th-century practice of train engineers calling signal aspects to their conductor (unless texting on their cell phone), with few if any automated systems to catch human errors. This safety philosophy is well-suited to the cost structure of the heavy freight rail business that dominates our landscape. On the opposite end of the spectrum, high speed rail safety relies almost entirely on avoiding a crash in the first place--not unlike airliners. In Europe, high speed trains zoom through dense fog at nearly 200 mph, with a train control computer watching over the driver's every move. Both philosophies achieve the intended level of safety, but what is supposed to happen when you need to mix both types of traffic on the same corridor, as is planned on the peninsula?

To their great credit, Caltrain is taking the national lead on the issue of mixed traffic regulations, as part of their plan to operate European-style passenger trains that are considered "non-compliant" with existing FRA safety regulations. As of September 2008, Caltrain staff estimated the likelihood of obtaining regulatory relief to be closing on 90 percent. That's very encouraging.

Caltrain's safety concept includes a radio-based positive train control system to be installed on the peninsula when the corridor is electrified, known internally as CBOSS (Communications-Based Overlay Signal System). This raises a host of questions, again moving beyond generic MOUs:

Why is Caltrain specifying CBOSS as a wireless system, excluding an entire segment of the wired train control market?

Is CBOSS an expensive re-invention of the wheel, where existing train control systems such as the Japanese Digital ATC and the European ETCS Level II might plug-and-play?

Why is Caltrain moving ahead with a solicitation this year, fueled by $500k in federal funds earmarked by congresswomen Jackie Speier and Anna Eshoo, for implementation in the next couple of years--before HSR train control requirements are fully defined?

Why should Caltrain be taking the lead on this critical technology issue, when the standard they develop will need to be applied California-wide to the entire HSR system and likely other HSR corridor traffic such as Metrolink, Union Pacific and BNSF?

Doing It Right

Sometimes, doing it right means stopping and charting a new course. One of the fundamental principles of good systems engineering is that you must develop a complete and concise set of design requirements before you dive into the detailed design of station platforms, overhead electrification or complex train control systems. Caltrain does not seem to have fully absorbed the extent to which HSR alters the requirements of nearly every improvement project in their pipeline. Preliminary design activity on all the above items should be slowed and resources re-allocated towards bringing the technical requirements and regulatory framework into better focus. The successful integration of HSR and Caltrain on the peninsula corridor depends on it!