Train Control Update

There have been two recent and important developments in the area of train control systems, the safety systems known in U.S. parlance as "Positive Train Control" or PTC.  Both of them have a direct impact on the future of the peninsula rail corridor.

CBOSS Goes Sideways

Caltrain's CBOSS project, criticized for years on this blog, is in ever deeper trouble.  According to Caltrain's latest project update, the $231 million previously allocated for this project are nearly spent, but the project is way behind schedule and struggling in the most perilous and delay-prone phase of all: testing of the integrated system.

Not Ready for FRA

Testing is where it all finally comes together, not in the carefully controlled environment of a lab test bench, but in the real world with all its ugly imperfections, annoying glitches, and external influences.  In each segment of the railroad, three things have to happen in sequence: (1) everything has to be fiddled with until it works; (2) when everything works, a dry-run of the official acceptance test, known as "Pilot Testing," is performed; and (3) the system is formally accepted after passing the official FRA-witnessed test of all its functions.  Caltrain's project is stuck in the "fiddle with it until it works" phase, helpfully diagrammed as an infinite loop in the test flow diagram at right, extracted from a CBOSS Verification, Testing and Inspection Plan filed with the FRA.  This is where the schedule and budget are blowing up, with Caltrain's next step described as "Complete Segment #3 Pilot Testing and FRA Witness Testing," coming as soon as they are "Ready for FRA," whenever that may actually be.

Caltrain's update mentions "software release delays" relating to the I-ITCS product that CBOSS is based on.  There are worrying signs that I-ITCS may become a technological dead end: the company that makes it, GE Signalling, was recently acquired by French rail giant Alstom.  Alstom's mainline signaling product portfolio does not give it top billing.  Furthermore, the FRA process is described as being "in flux", meaning that the goal posts are moving.

What we have here is a classic foundering IT project, and it isn't clear if throwing more money at it (at a burn rate of about $50M/year) is going to save it.  With the federal PTC implementation deadline now pushed out to 2018, this is a good time to stop and re-assess the project before escalating the commitment.

HSR Buys Radio Spectrum

Meanwhile, the California HSR Authority is about to spend $50 million to secure the rights to a key chunk of radio frequency spectrum.  The frequency bands being purchased are 757-758 MHz and 787-788 MHz, not the usual 220 MHz band used for freight PTC systems.  Instead, the CHSRA has documented its intent to deploy ERTMS, an increasingly mature and proven train control standard that originated in Europe and is increasingly in worldwide use.  The two bands purchased for HSR are not sufficiently wide to deploy GSM-R, the obsolescent communications standard currently used as part of ERTMS.  It is more likely that California's deployment of ERTMS will use a more modern, secure and spectrum-efficient LTE communications layer, following the evolutionary path beyond GSM-R already being planned for ERTMS.

Connecting the Dots

Suppose the following conditions come to pass:

1. CBOSS proves unworkable (increasingly likely)
2. HSR shifts its focus to Northern California (possible)
3. HSR finalizes plans for ERTMS as its high-speed train control standard (very likely)
4. Due to construction delays, HSR needs new and productive ways to spend federal funds that expire by 2017 (possible)

Then an opportunity exists to deploy a train control pilot project on the peninsula rail corridor, using ERTMS with LTE communications in the 700 MHz band.  This scenario recognizes an important fact so far disregarded by Caltrain, that HSR will become by far the largest tenant railroad on the peninsula.  Ignoring this fact is an odd position to take for a railroad that hangs its future on "blending" with HSR.  Caltrain will surely dislike the idea, bleating about closer headways, crossing signal integration, station stop enforcement and other completely unproven bells and whistles--as they have since 2009--but events are now quite clearly bearing out the relative technological merits of ERTMS and CBOSS.  It's just sad that it took a quarter of a billion dollars to settle the question.

In the unforgiving world of system integration testing, reality always wins.

U.S. Supplier Enters ERTMS Market

In a move that amounts to a clear acknowledgement of the increasing worldwide supremacy of the ERTMS ("European" Railway Traffic Management System) technology standard, General Electric Transportation Systems recently became the first U.S. signaling supplier to enter the ERTMS market.

GE Transportation Systems is the same company slated to supply the on-board and wayside components of CBOSS, Caltrain's new-fangled train control system that will be paid for with HSR funding while being technically incompatible with the HSR train control system.

One could briefly entertain the illusion that common sense might prevail, and that with a minimum of contractual upheaval CBOSS could evolve into the first U.S. installation of ERTMS, a solution that could eventually be extended to the entire California HSR system.  Unfortunately, in the blinkered world of parochial agency interests, spending money (over $200 million of it for SF - SJ alone!) is a higher aspiration than providing a good technical solution.  Compatibility is for sissies; why do it right when you can do it twice?

ERTMS Coming To California

The CHSRA recently added to its collection of technical memos a White Paper on train control technology for California's high-speed rail system.  The selected train control system will likely be deployed on the peninsula rail corridor later this decade or in the early 2020's, regardless of what "solution" Caltrain may pursue in the interim.  The CHSRA's experts looked far and wide for the best technical solution, and as longtime readers of this blog may have guessed, they conclude as follows:

The sole technology that is fully compliant with all of the CHSRA project and technical requirements is the European Rail Traffic Management System (ERTMS) European Train Control System (ETCS) Level 2 with Global System for Mobile Communications – Railway (GSM-R). ERTMS is service-proven and its attributes are highly applicable to CHSTP automatic train control (...)

The biggest technical obstacle for importing ERTMS to the U.S. is the lack of available radio frequency spectrum.  The White Paper delves into great detail about possible ways to overcome this, making several important policy statements along the way:

• The choice of train control technologies will be limited to solutions that have been successfully demonstrated at high speeds for a period of at least 5 years, to minimize implementation risk and enable a strong safety case to be made to the FRA.
• The CHSRA requires that it not be locked into a single source for procurement, bidding, and supply. Interoperable, interchangeable, open standard and multi-vendor solutions are required and will provide the CHSRA with several sources of supply for extensions, upgrades, and maintenance spare parts in the present and future, thereby lowering risk and cost. (Are you listening, Caltrain?)
• Other alternatives to ERTMS are not technically compliant, not compliant with the project requirements, or present too much risk to implementation.

As it happens, the coveted ERTMS / ETCS Level 2 is transparently compatible with ERTMS / ETCS Level 1, which the White Paper describes as follows:

ETCS level 1 is designed as an add-on to or as an overlay on a conventional line already equipped with wayside signals, and possibly as a fallback solution from ETCS level 2. Communication from the track to the train is ensured by dedicated balises located on the trackside adjacent to the wayside signals at required intervals, and connected to the nearby interlocking and/or wayside signals.. The balises have a data connection to the ATC equipment which provides movement authorities for transfer to the train. Receiving the movement authority through balises, the ETCS onboard equipment automatically calculates and indicates to the train engineer maximum permitted speeds of the train and the next braking points if needed, taking into account the train braking characteristics and the track description data. This information is displayed to the train engineer through a dedicated screen in the cabin. The speed of the train is continuously supervised by the ETCS onboard equipment.

This is of course precisely the same thing as CBOSS, which Caltrain and their vendor Parsons Transportation Group are now kludging together for us for a hefty wheel-reinvention fee.

We've already seen Caltrain work with FRA bureaucrats to avoid re-inventing a double-deck EMU train.  Why can't they also work with CHSRA, FRA and FCC bureaucrats to avoid re-inventing a train control system?  The CHSRA is already putting together a plan for scaling the regulatory mountain, with more detail on radio frequency spectrum acquisition provided in TM 300.03 EMT Radio Frequency (RF) Spectrum Acquisition Strategy.

It's no longer just a blogger saying it (bloggers don't know what they're talking about): the high-speed rail project is now firmly on the record as preferring ERTMS as the sole solution, and is already working with government and private entities to obtain the necessary radio spectrum to deploy GSM-R in California.  ERTMS is the best solution for the peninsula, because it would allow high-speed trains to use Caltrain tracks with no special equipment or modifications.  As a side benefit, it would also allow Caltrain to meet their PTC requirement at minimal cost and risk.

ERTMS is coming.  Your move, Caltrain.

Meanwhile, in Rio...

It finally happened.

Last Thursday, Caltrain's board authorized the award of the first phase of a $138,135,673 contract to Parsons Transportation Group to design, procure and install the Caltrain-specified CBOSS train control system (see staff presentation).  This Parsons contract forms the lion's share of a total project budget variously reported as $231 million to $251 million, or a whopping $5 million per route-mile.  According to a project schedule, the final acceptance of the system is planned for February of 2016 (52 months from now), but that assumed contract award at the May board meeting (5 months ago).

Viewed in the framework of the U.S. transportation industrial complex, where public agencies such as Caltrain transfer huge sums of taxpayer dollars to large private corporations that thrive on custom-engineering, re-engineering and over-engineering everything, this contract is business as usual, and Caltrain will probably end up, years late and millions over budget, with a partially functional PTC system.  That sets the stage for more years and millions spent to make it work with high-speed rail.

Meanwhile, in Rio...

Meet SuperVia, a commuter rail operator in Rio de Janeiro, Brazil.  SuperVia is one busy system, even busier than BART.  Here's a quick comparison between Caltrain and SuperVia:

	Caltrain	SuperVia
Route Miles	77	140
Routes	1	5
Trains	about 25	about 160
Stations	31	89
Weekday Ridership	~45,000	~540,000

Like Caltrain, SuperVia is modernizing.  Among other improvements, SuperVia is installing a sophisticated positive train control system to enforce speed limits, prevent collisions, and reduce the headways between trains.  Unlike Caltrain, SuperVia chose to adapt their requirements to what suppliers already had on the shelf, and is procuring an ERTMS Level 1 overlay system from Bombardier Transportation through a contract worth 125 million Real, or about US $70 million.  (Note that the unknown scope of this contract makes it difficult to compare directly to CBOSS; for example, Bombardier's contract is unlikely to include the train-borne components.)  ERTMS, to remind everyone, is a train control standard that is quickly catching on worldwide, except here in the protected U.S. signaling market.

ERTMS Level 1 is exactly the sort of standardized train control system that would be transparently compatible with high-speed rail, which will most likely operate on its own dedicated high-speed trackage using ERTMS Level 2, a much more sophisticated version of the standard that does away with wayside signals.

The kicker?  Bombardier promises to put this new overlay signaling system into service on SuperVia's various lines from November 2012 to July 2013.  Here's how that stacks up against Caltrain's CBOSS:

	Caltrain CBOSS	SuperVia ERTMS
Contract award	October 2011	May 2011
Initial service entry	October 2015	November 2012
Final delivery	February 2016	July 2013
Time from award to initial service	48 months	18 months
Time from award to final delivery	52 months	26 months

It's too late now to do anything about CBOSS, but it sure will be interesting to see what PTG and Bombardier will deliver for each respective rail system.  Can PTG and Caltrain come up with an ersatz-ERTMS by 2015 for the promised sum?

News Roundup

Rubber Stamp

Mike Rosenberg pens a scathing indictment of the Peninsula Corridor Joint Powers Board that runs Caltrain, calling out the board for rubber-stamping everything that is submitted to it by Caltrain staff (including, presumably, the MOU with high-speed rail). The number of Yes votes since the last dissenting vote: 1,591. With only 9 board members, that's 176 consecutive unanimous Yes votes!

One of the dangers of having staff run the show is that an organization will pursue projects for their own sake, to perpetuate its own bureaucratic existence. Case in point: Caltrain's CBOSS train control project, where a small back-and-forth transit operation runs amok with a $230 million technology research and development project that is almost certainly doomed to development failure. Speaking of train control...

ERTMS on the Peninsula?

The CHSRA staff memo for the recent board meeting happens to tally the money currently allocated for HSR in California. One of the items is $16 million of ARRA stimulus money, previously requested as an ear-mark for CBOSS, but now described as funding the "design/implementation of the first Positive Train Control/ERTMS interface implementation on the Peninsula." Say what?

(to find out what the acronyms CBOSS and ERTMS describe, please read here.)

An optimist would note this is the first time that 'ERTMS' and 'Peninsula' are mentioned in the same sentence in official agency materials, rather than just a blog. That much is encouraging.

A pessimist would note that "interface implementation" means an interface between the existing ERTMS and Caltrain's proposed CBOSS, assuming they would co-exist. This is the worst of both worlds: not only is CBOSS 100% functionally redundant with ERTMS, i.e. it will do the exact same thing that ERTMS already does, but interfaces between multiple complex safety-critical systems are astonishingly expensive to implement successfully. If CBOSS wasn't enough of a promise of years of delay and cost blowouts, then kludging ERTMS on top of CBOSS is an absolute guarantee.

The high-speed rail project has very strongly implied that ERTMS would someday be installed on the peninsula. The recent train control technical memos (see TM-3.3.x) explicitly state that the selected technology must already exist as part of an operating system with proven experience worldwide on at least one high-speed passenger railway. That leaves exactly two solutions: (1) the ERTMS standard supported by the world's biggest names in train control, being deployed in dozens of countries worldwide, and (2) the Japanese Digital-ATC product by Hitachi, deployed in Japan and Taiwan. Wanna place bets?

Show Some Teeth, For Once!

One thing the Caltrain board of directors might consider sinking its teeth into (if it has any?) is the CBOSS fiasco-in-the-making. The correct answer, for a small fiscally-vulnerable operation like Caltrain, is to use tried and true solutions whenever they are available. When the wheel already exists (ERTMS) you don't take the risk of re-inventing the wheel (CBOSS), especially when HSR has already telegraphed its intent to deploy ERTMS and might even pay for it!

At this point, a few wrong moves like CBOSS can quite literally end Caltrain's chances of survival.

Strange Bedfellows Indeed

The June 2nd CHSRA Operations Committee meeting audio recording included some interesting information that was neither in the agenda nor in the PowerPoint slides, regarding the relationship between Caltrain and the CHSRA.

The True Meaning of Track Sharing

The following exchange took place between Rod Diridon, board member of the CHSRA, and Tony Daniels, the program manager for the entire technical effort--a sort of godfather figure of the HSR project. They had been discussing and praising Caltrain's recently obtained FRA waiver, which allows Caltrain to operate European-style electric trains provided that certain conditions are met. Here's where the discussion went next:

Diridon: The joint track waiver that FRA is going to be giving now to Caltrain, is for them to use diesel and electric, their electric, not our vehicles, on their track.

Daniels: Right. Compliant and non-compliant is the best way to look at it.

Diridon: I understand. But to be more graphic here, it's the difference between using diesel locomotives and the lighter European or Asian type electric powered vehicles.

Daniels: Only for passengers. No freight.

Diridon: For passenger service, on the same track.

Daniels: Not freight.

Diridon: Right, and of course that assumes positive train control.

Daniels: Yeah.

Diridon: Have we thought about using their tracks for our … locomotives, or…

Daniels: We are. We are doing it…

Diridon: I meant their double-track system for our system.

Daniels: We are doing it.

Pourvahidi: Instead of our tracks, instead of having our tracks?

Diridon: No, I don't see in our alternatives any place…

Daniels: No no just, sorry, (…) it's not that we can't run on it, we can, if it was necessary, in the same way as the Caltrain trains can run on ours, our so-called tracks. It's just that there's not the capacity.

Diridon: Well I understand capacity.

Daniels: Right. But you can't work on either. We're planning to keep them separated except when you come in from Bayshore into 4th & King and ultimately Transbay, we have to mix ourselves on the track. As we go into Transbay, for example, we'll use the same track going in.

Diridon: Though we certainly wouldn't prefer it. But if we were stuck along the peninsula someplace with no more than a two-track system, … have you thought about that?

Daniels: Uhhh, it would change completely the whole plan. Right now, we're kind of…

Diridon: I'm not proposing it. Don't misunderstand me.

Daniels: We looked at it operationally, at 60,000 feet, and just… we're talking 22 trains an hour. That's not on, you can't turn around.

Diridon: You mean at maximum, there's 22 trains an hour. Not to begin with.

Daneils: No, but ultimately, when you're starting, you're going to be on the order of something like 18 trains an hour. Then you've got to turn them around at the other end. That's where the difficulty is, not running them on the tracks.

Diridon: You're talking about Caltrain now?

Daniels: Yeah. You can't turn that number of trains around at the terminal end.

The key nugget is highlighted in red. Despite Caltrain's dogged insistence to the contrary, the CHSRA does not, repeat, DOES NOT, plan to share tracks with Caltrain on the peninsula. Their plan is to have their own pair of exclusive-use tracks all the way up to Bayshore. Those HSR tracks could only be "shared" by Caltrain under rare circumstances when another track is out of service--a sort of breakdown lane, and certainly not a mixed-use corridor that would allow Caltrain to provide both frequent AND fast service.

This can and should be construed as a downright rape of Caltrain. HSR is going to be brutishly rammed up the peninsula corridor without due regard to the enormous benefits that a truly shared corridor could provide for peninsula commuters--whether they ride the train or drive.

Keep Your Hands Off My Stimulus

Another interesting exchange occurred regarding the $2.3 billion of federal stimulus funding that the FRA has awarded to California. As noted repeatedly at the operations committee meeting, the late 2011 deadline for stimulus funding is extremely tight, with environmental clearance (a.k.a "shovel readiness") of the peninsula high-speed rail project unlikely to be obtained, let alone litigated. Sensing the possibility that this time-critical federal funding could slip away to other parts of the state, the Bay Area congressional delegation is supporting Caltrain's effort to jockey for some of the HSR bacon.

Diridon: Also, when would be an appropriate time to talk about the impact of the attempt by the Caltrain system to acquire ARRA funds directly.

(…)

Daniels: I think that's a separate matter for the authority, I think, to try and resolve what… is Steve Schnaidt [legislative affairs consultant] here? Because he brought this up as an item that we need to try and resolve, because there is some conflict between what the peninsula wishes to do and what we're doing on the high-speed rail, and that has not been cleaned up yet, I don't think.

Diridon: Can I ask a further question there, sorry to take so much time. [Friendly banter about Diridon taking so much time.] It seems to me that the environmental clearances that the Caltrain system has, that they want to fund, are based on a Caltrain type of service.

Daniels: That's right.

Diridon: Not on a four-track system.

Daniels: Correct.

Diridon: As a consequence, if you're talking about attempting to use ARRA funds to do their electrification on a two-track system, or to do grade separations on a two-track system, it's counter-productive to our objectives. Is that not a factual statement?

Daniels: It is and it isn't. It's not a black-and-white answer. I mean you could structure it, if you could do it under the environmental, our high-speed rail environmental process, it would help ultimately the building of our piece of it. You could state it that way, but …

Diridon: I absolutely understand that we could meld their clearance into ours and modify their clearance to include a four-track system instead of a two-track system or elevated or whatever ours is going to be. But the clearance that they have now, that they're trying to rely upon in order to qualify for ARRA funds directly, is based on a two-track system--on-grade, two-track system--which may not be what comes out of our study.

Daniels: It's very unlikely it will. We will be, we know already from everything we're doing that it's a four-track system to make it work for both sets of operations, commuter and high-speed rail.

Diridon: So, at some point Mr. Chairman we need to have a conversation on this subject. Because if ARRA funds go in to build for example an undercrossing for a two-track system, we then come along at a point in the future with a four-track system, that has to be accommodated by the undercrossing, we have to rebuild the undercrossing. That's the worst kind of government. We don't want to be tearing up brand new projects in order to change something.

Daniels: Well here's the answer to that movie, Rod. The question that we raised right at the beginning of them having some guidance from the FRA about how we're going to put these ARRA funds together will include whether we can or cannot do what you've said. On first glance, I don't think you can, because the ARRA funds are supposed to be for high-speed trains, and a two-track commuter line is not a high-speed train.

Let the games begin. As a clarification, Caltrain board has not actually certified the electrification EIR just yet. That action, unexpectedly held up last April, is reportedly slated for early July.

A Compromise Solution?

One of the many strings attached by FRA to their Caltrain waiver is that positive train control must be installed, tested, and FRA-certified before Caltrain can carry even a single passenger on an electric train. That puts PTC in the critical path. Unfortunately, Caltrain's PTC plans do not jive with high-speed rail's PTC plans. That lack of jive makes it exceedingly unlikely that ARRA high-speed rail money will be allowed to fund Caltrain's PTC project. In these lean times, just where is Caltrain going to find $230 million (opening bid!) to build something that's incompatible with high-speed rail?

A far better approach would be to grant Caltrain some ARRA money to become the first installation of ERTMS in the United States, blazing the path for high-speed rail. Everybody wins: Caltrain gets a lower-risk, timely PTC solution with funding to back it up--and HSR gets the bureaucracy of importing and tailoring ERTMS taken care of early, a state-wide benefit that is far from a parochial peninsula interest. With a viable PTC program in place, it might even make sense to start thinking of funding some Caltrain electrification infrastructure--infrastructure that would be quite useless without PTC. See the Catch-22?

When you're in a hole, the first thing to do is stop digging.

First Nail in the CBOSS Coffin

Buried deep in the CHSRA's March 3rd Operations Sub-Committee meeting, in a progress report briefing prepared by the Program Management Team (Parsons Brinckerhoff), are the following little gems (boxed in red):


The acronyms ERTMS, ETCS and GSM-R refer to the European Railway Traffic Management System and its components (the European Train Control System and the GSM-Railway cell data standard). The completion levels for these documents suggest that ERTMS has already been selected as the train control technology for the California High Speed Rail System. Quite wisely, the project appears to have selected an off-the-shelf technology standard that was developed and debugged using billions of Euros of OPM (Other People's Money).

Meanwhile, spunky little Caltrain continues to believe it can single-handedly develop an entirely new train control technology known as CBOSS (Communications-Based Overlay Signal System), which is functionally redundant with ERTMS / ETCS. (For more background about these technologies, see Peninsula Train Control: PTC, CBOSS and ERTMS.)

The design, integration, testing, and deployment to commercial service of CBOSS is estimated to cost $231 million, before the cost overruns and schedule delays inevitably associated with this type of development effort. While some of this funding was expected to come from the $2.25 billion California HSR stimulus award, how likely is the CHSRA to fund the CBOSS project if it has already selected ERTMS for itself?

Caltrain needs to wake up and stop striving for compatibility with freight PTC. The correct solution is to abandon CBOSS, join forces with the CHSRA to bring ERTMS to the United States, and implement an integrated Caltrain / HSR train control system. Navigating the bureaucratic hurdles of importing ERTMS, ETCS and GSM-R is likely to be far quicker, easier and cheaper than trying to re-invent the wheel with CBOSS. That's especially important because Caltrain's fleet replacement effort cannot proceed until after a robust train control solution is in place. The clock is ticking as Caltrain's antiquated diesel trains fall further into obsolescence, and failure is not an option.

This appears to be the first nail in the CBOSS coffin.

Peninsula Train Control: PTC, CBOSS and ERTMS

Trains on the peninsula today rely on light signals placed next to the tracks that indicate whether it is safe to proceed. In order to safely operate a train, the crew must view and interpret these signals, a process that is inherently vulnerable to human error. While error-prevention protocols are in place to minimize the likelihood of such errors, they can still happen, with deadly consequences.

Positive Train Control

Positive Train Control (PTC), a means to prevent accidents due to train crew errors, has been a priority of the National Transportation Safety Board since the 1970s. The recent Chatsworth accident, where a train engineer missed a red signal because he was texting on his cell phone, moved the federal government to mandate the installation of PTC on all passenger railroads and freight main lines by December 31st, 2015.

Positive Train Control is achieved by hardware and software that continually monitors and enforces the train crew's compliance with movement authority (the permission to occupy a portion of track for a certain distance, time, or speed), and intervenes in case of human error. PTC consists of three major functions:

• preventing train-to-train collisions
• preventing trains from exceeding speed limits
• protecting work zones with personnel near or on the tracks
  

PTC is not just hardware and software; it is a function. PTC is not new; there are many existing train control systems in operation around the world that implement some or all functions of PTC. PTC is not foreign; it already exists on several passenger railroads in the United States (most notably on Amtrak's Northeast Corridor) and is common in urban rail systems such as BART.

The Federal Railroad Administration has issued a Notice of Proposed Rule Making detailing the regulatory requirements with which all PTC systems must comply. Besides describing the history and context of the new rules, the NPRM specifically states that "wherever possible, FRA has attempted to refrain as much as possible from developing technical or design standards, or even requiring implementation of particular PTC technologies that may prevent technological innovation or the development of alternative means to achieve the statutorily defined PTC functions." Appropriately, PTC is being defined as a function, not a product.

Efforts to implement PTC products have been afoot for years. The freight railroads are now chafing at the scope and cost of the unfunded PTC mandate, calling into question whether it can be met by 2015. Five years is a short time to standardize a technology and to deploy it on a grand scale--over 30,000 locomotives and 100,000 miles of track for just the five largest freight railroads.

The Universe Beyond PTC

As narrowly defined by the FRA, Positive Train Control by itself does not suffice to run a high-speed passenger railroad. Achieving a safe flow of rail traffic requires myriad systems that generate and communicate movement authorities to each train, perform track clear detection (when a portion of track is free to be entered by a train), dispatch and optimize traffic flows, monitor system status and health, and even drive the trains in the smoothest and most energy-efficient way. These systems are known by an alphabet soup of acronyms that are often specific to signalling practice, railroad culture, or specific products in various countries. Those who wish to dig deeper might read the book Railway Operation and Control by Joern Pachl, for an accessible and culturally comprehensive overview of quite a complex subject.

Today, Caltrain uses a widespread technology known as Centralized Traffic Control (CTC). A dispatching office in San Jose operates the peninsula corridor by remote control, through relay-based logic that safely sets all switches and signals. The train crew is responsible for observing signals and speed limits, and may communicate with the dispatcher by voice radio. This system is ill-suited to running high traffic densities at high speeds; therefore, an improved signal system is considered a top priority in the Caltrain 2025 plan (now being merged into the Peninsula Rail Program). That system is known internally as CBOSS.

Caltrain's CBOSS

CBOSS, or Communications-Based Overlay Signal System, implements PTC functions and many additional features. Its key benefits are stated to be:

• increased safety, implementing all three functions of PTC
• increased capacity of the peninsula corridor, as measured in trains per hour
• enforcement of traffic separation between freight and passenger trains, to support Caltrain's transition to lightweight EMUs
  
• reduction of crossing gate down-times

CBOSS is an overlay system, in that it makes few changes to the underlying vital infrastructure that controls trains on the peninsula, namely the signals, interlockings and Centralized Traffic Control used to generate and communicate movement authorities, and the track circuits used for track clear detection and grade crossing protection. One of the key design drivers for CBOSS was to avoid altering or replacing this infrastructure, gradually built up in the last fifteen years within Caltrain's limited budget.

Like many modern train control systems, CBOSS consists of train-borne equipment, wayside and track equipment, a dedicated radio communication network, and an interface to the dispatching center. There are plans to reuse as much hardware and software as possible from the emerging PTC systems being developed by and for the freight railroads.

CBOSS Meets HSR

In November 2008, after CBOSS specifications were well underway, high-speed rail suddenly became a realistic prospect rather than a distant fantasy. Sharing the peninsula corridor with HSR has enormous implications for CBOSS. Consider the changes:

• The peninsula corridor will become a small portion of the future statewide HSR system.
• To operate at 220 mph in all weather conditions (e.g. Tule fog), high-speed trains will be fitted with train control systems that may be different, more sophisticated or more capable than CBOSS.
• Grade crossings, a major focus area for CBOSS, will largely disappear from the peninsula.
• All track circuits, signals, interlockings, etc. will be reconfigured or replaced when tracks are added or modified.
• The high speed rail project has far deeper pockets than Caltrain, so retaining existing infrastructure is less pressing a concern because economies of scale can be realized statewide.

HSR brings one undeniable advantage: financial resources that dwarf anything that Caltrain could muster by itself. Thanks to HSR, CBOSS figures prominently in the short-term funding strategy for the peninsula corridor, with $230 million requested in the MTC's Peninsula Corridor Investment Strategy. The contract to build CBOSS is due out to tender in November 2009.

Train Control Systems Are Hard

Developing, integrating, testing and deploying safety-critical software and hardware is no picnic. It is neither easy, quick, nor cheap, especially when the technology is new. The recent history of train control system development, even here in the Bay Area, is littered with projects that were delivered years late, millions over budget, or even not at all. Without fail, new train control systems follow the development profile shown in the cartoon at right.

• BART developed a new signalling system known as AATC (Advanced Automatic Train Control) starting in 1998. Difficulties with integrating the software with the hardware eventually forced BART to scrap AATC in 2006 after $80 million had already been spent.
• MUNI's Advanced Train Control System, intended to improve capacity of the MUNI Metro, was late, over budget, and did not perform as intended. It caused the spectacular MUNI Meltdown in 1998, and still struggles to achieve its performance objectives.
• Amtrak developed an overlay PTC system for the Northeast Corridor known as ACSES, to supplement the legacy cab signal system. Derived from a French technology, it entered testing in 1996 and did not achieve reliable data radio operation until 2005.
  
• ERTMS, the European Railway Traffic Management System, is probably the most ambitious system development in the last decade. ERTMS attempts to unify technology and operating practices across Europe. Its development was dogged by requirements instability, and its high cost made for a questionable business case where existing train control systems already functioned adequately. A software error even caused a minor accident in 2007. Deployment is years behind schedule and massively over budget, with major fiascos in the UK and the Netherlands.
  

These examples illustrate the enormous--and systematically under-appreciated--risk that is inherent in developing and deploying sophisticated new safety-critical embedded systems.

One can reasonably infer that it is exceedingly unlikely that Caltrain, but a small speck in the universe of passenger rail, can single-handedly develop something as technically complex and refined as CBOSS within any reasonable schedule or budget--much less if it hitches its wagon to freight PTC. The HSR project raises the stakes even higher than the FRA PTC deadline, because CBOSS must first work reliably to enable the construction of HSR infrastructure while maintaining Caltrain operations. A failure would be compounded--imagine Caltrain's CBOSS program delays cascading to the statewide HSR system, resulting in idle tracks with no trains. Despite the best intentions and deep expertise of the development team, the chances of a fiasco are alarmingly high.

Of course, this nightmare scenario is not a foregone conclusion, although one would hope that the mere prospect would be considered one of the highest risks to the Peninsula Rail Program, whether on technical performance, cost, or schedule.

CBOSS compared to ERTMS

The CBOSS project has ambitions that reach beyond Caltrain. A report states that "Caltrain has noted with some focus that if desired or required, CBOSS is capable of being readily extended, not only to adjacent properties, but broadly within the industry to ensure solid and sustained support within the industry." There's even hopeful talk of CBOSS being considered for HSR. Since CBOSS wants to play in the big leagues, it’s only appropriate to compare it to the current state of the art, namely ERTMS (the European Railway Traffic Management System, often referred to by its component system ETCS, the European Train Control System). Why ERTMS, despite the development failures cited above?

In short, that was then, this is now.

ERTMS is now over the development "hump" and is gradually maturing to the point of becoming a worldwide standard in passenger rail applications. Despite its European origins, it is now being deployed in many countries outside of Europe; it's hard not to notice Australia, China, India, Saudi Arabia, South Korea or Taiwan jumping on the ERTMS bandwagon.

The following comparison points out key differences between CBOSS and ERTMS:

Who controls the specification
CBOSS: Caltrain	ERTMS: UNISIG, a consortium of suppliers, and the ERTMS Users Group in Brussels, composed of European rail administrations.
Is it a standard?
CBOSS: No, although it’s envisioned to spread beyond Caltrain.	ERTMS: Yes. Does not belong to any operator or vendor. Once agreed upon, the standard is administered by the European Railway Agency.
Requirements maturity
CBOSS: Low to moderate. All reviews are performed by stakeholders (Caltrain, consultants, FRA, vendors) who have an interest in CBOSS going ahead as planned. No independent requirements validation performed other than expert consensus on the specification. Heavy reliance on expertise of developers.	ERTMS: Moderate to high, after a long period of requirements instability. Requirements honed by many organizations that set aside their respective technological and cultural traditions. Initial deployments are complete, requirements are stabilizing, and validation experience is being fed back into the ETCS 3.0.0 System Requirements Specification due out in 2012, the culmination of nearly two decades of development.
Development risk
CBOSS: Development “hump” looms ahead. Risk managed by "debate" instead of formal systems engineering risk management methods. Caltrain / Peninsula Rail Program implicitly take on all technical, schedule and budget risks, with CBOSS and PTC squarely in the critical path of the Peninsula Rail Program.	ERTMS: Already developed and de-bugged using a lot of other people’s sweat, pain, and money. ERTMS is over the development "hump" and the majority of risks have now been retired. The proof is in the pudding: for example, Mattstetten - Rothrist in Switzerland is operating at 242 trains/day with headways of 110 seconds and speeds of 200 km/h.
Development expense
CBOSS: High. In its first phase, this is undeniably a research and development project. The rigorous testing and certification of safety-critical software and hardware is not cheap, especially when requirements instability causes several rounds of change orders and regression testing.	ERTMS: Low, provided the standard is complied with. Development is complete and the system is already in wide operation. Non-recurring expenses would arise primarily from bringing ERTMS to the U.S. for the first time.
Deployment expense and economies of scale
CBOSS: Recurring cost expected to be low, due to reuse of hardware and software designed for freight PTC (e.g. low-cost wayside interface units). Leverages the economies of scale from a PTC installed base that is planned to rapidly surpass ERTMS.	ERTMS: Perceived to be high, because of the complexity of the system. While multiple vendors exist, they operate as a consortium (UNISIG) that may function as a de-facto cartel. Some economies of scale realized across many international installations, although they may not be passed on to customers.
Radio communications infrastructure
CBOSS: Undetermined, although IEEE 802.11n (Wi-Fi) or 802.16e (WiMAX) is possible.	ERTMS: Dedicated GSM-R digital cellular voice & data. GSM is an aging "2G" standard that will soon be obsolete, and the wayside infrastructure is expensive to install. Radio spectrum does not currently exist, and would need to be allocated by the FCC outside of commercial GSM cell networks.
Support for highway grade crossings
CBOSS: Enables “smart” crossing gates that stay open when a train makes a station stop just short of the crossing. Enables real-time health monitoring of crossing warning devices, with automatic train speed restriction in case of failure. These capabilities will be developed despite the high probability that Caltrain will be largely grade-separated for HSR.	ERTMS: Does not integrate with grade crossing warning devices, which remain a separate system.
Support for high speed rail
CBOSS: Claimed to be fully compatible, to the extent that developers have experience with foreign HSR systems. There has been no explicit engineering coordination between CBOSS developers and the CHSRA and its consultants (besides a few consultants moving from CBOSS to the HSR project), and California HSR requirements and design criteria are undetermined.	ERTMS: The new standard for high-speed rail in Europe, used on nearly every high-speed line opened to service in the last five years. Used at 500+ km/h during 2007 rail world speed record. Worldwide standard for green-field HSR installations (China, Argentina, etc.)
Interoperability
CBOSS: Based on freight PTC technology, so freight PTC equipment (UPRR and Amtrak) can operate seamlessly on the peninsula.	ERTMS: Would require installation of train-borne equipment in addition to PTC, for any UPRR or Amtrak trains operated on the peninsula (e.g. using a surplus Caltrain diesel on the front of the train). On the other hand, if the ERTMS standard were selected for California HSR, compatibility with HSR would be built-in from the start.
System of units
CBOSS: United States customary units.	ERTMS: Metric system, requiring conversion of all legacy documentation, databases, and equipment.
Flexibility
CBOSS: Allows the definition of up to 64,000 train performance profiles.	ERTMS: Allows only 18 (?) different train performance profiles. (section 3.13.2.2 of the ETCS specification)
Risk of vendor captivity
CBOSS: High. Despite its ambitious vision, Caltrain remains a tiny operation with less than 50 route miles and $100M yearly operating budget. The entire CBOSS contract will be awarded to one winning bidder, and Caltrain would have no back-up if the vendor lost interest in the product. (This happened recently with Caltrain's dispatching software, instantly made obsolete when the vendor walked away from the product.)	ERTMS: Low. Multiple vendors including some of the biggest names in the business, although without a large U.S. presence due to the protectionist stance of the industry. Wide range of off-the-shelf products, in conformance to mature and widely-used standards specifications. Growing installation base guaranteed by European mandate.
Country of origin
CBOSS: Made in the U.S. of A. using All-American stimulus dollars.	ERTMS: Not Invented Here. Has letter ‘E’ in acronym.

The Case Against ERTMS

Most arguments against the suitability of ERTMS for the peninsula corridor, advanced by a key CBOSS developer, fall into three broad categories.

• The Exception Hypothesis: Caltrain is different, unique, and special. Mixed train performance, grade crossings, etc. require a special system that mitigates operating hazards that are unique to Caltrain. The new train control system must accommodate all operating rules. Outside people just can't understand the unique operating needs and environment of Caltrain.
  
  
• Blind Faith in U.S. Freight PTC: Caltrain must use a system that is interoperable with freight trains, especially on the Gilroy branch. Freight PTC is a mature technology that will become a standard and be deployed nationwide by 2015. Freight PTC is the ideal base for Caltrain's needs, and reuse of freight PTC components will guarantee low costs. Caltrain must use a radio system that operates within legacy railroad frequencies.
  
  
• Not-Invented-Here Syndrome: U.S. railroad folks are a conservative bunch, and ERTMS would be too much change to swallow at once. ERTMS does not meet Caltrain's operating needs or U.S. operating practices. ERTMS isn't PTC. ERTMS still doesn't work. ERTMS contains latent software bugs that will degrade safety and might cause a fatal accident. ERTMS is not interoperable with U.S. freight trains. ERTMS is metric. (yuck!) ERTMS is controlled by European bureaucrats and the U.S. had no input to the specification. ERTMS can't be used as-is and must be modified at great expense--and bastardizing ERTMS is worse than developing something new and better.
  

Most of these arguments boil down to pounding the pulpit. News flash: Caltrain is an insignificant, two-track back-and-forth operation with sparse traffic, no complex junctions, and a tiny fleet. It will remain so for the foreseeable future.

The Case For ERTMS

Suppose that Caltrain's primary business is to carry passengers, and not to undertake major new technology development projects with a price tag more than twice annual revenue.

Suppose that a CBOSS development failure is actually not an option, since it would snarl the entire Peninsula Rail Program.

Suppose that there are many program risks that threaten the smooth execution of the Peninsula Rail Program, and that CBOSS development risk borrows more trouble than it's worth when demonstrated solutions exist.

Suppose that using a train control system shared by Caltrain and HSR is actually desirable, for a rail corridor shared by Caltrain and HSR (minority freight traffic notwithstanding).

Suppose that Caltrain developing a new train control technology for HSR amounts (at best) to the tail wagging the dog, or (at worst) to the future need for redundant on-board equipment on every single high-speed train in California.

Suppose that operating rules can be tailored to the technology, rather than demanding that the technology conform totally and completely to operating rules and "elicited needs." (with the added opportunity of invoking paragraph 8.3.(c)... hint hint)

Suppose that being locked into a single vendor does not promote vigorous competition and healthy long-term viability of your supplier base.

Suppose that freight PTC might not become all that it's cracked up to be, especially not by the 2015 deadline of the government's unfunded mandate, forcing Caltrain to continue operating obsolete, unreliable diesel trains long past their expiration date.

Suppose that Caltrain is capable of the same zeal and pragmatism in pursuing FCC spectrum for GSM-R (or any other minor regulatory obstacle) as they display when running the red tape to import off-the-shelf European EMU trains that are "non-compliant" with FRA regulations.

If these suppositions sound remotely reasonable, then the Peninsula Rail Program should take the bold and visionary step of adopting ERTMS--warts and all. ERTMS would mitigate development risk, guarantee future compatibility with HSR, and avoid dependency on a single vendor.

If these suppositions are false, then maybe it's time to invent a better mouse trap than ERTMS. Best of luck with that.