First Look at Electric Service

Caltrain's proposed weekday peak service

Caltrain has started to pull back the curtain on their fall 2024 service pattern, when the electric fleet will (finally!) enter service.

The peak service pattern is depicted at right from a Caltrain slide, and looks like this in a string diagram from our trusty taktulator. The overall score for this timetable is a lukewarm 115 points relative to the benchmark score of 100 for the 2011 timetable, and it requires just 14 trains to operate, not counting spares.

The Good

• Peak frequency will remain at four trains per hour per direction until ridership recovers more. This requires a waiver from the FTA, which originally made its funding contingent on operating six trains per peak hour per direction.
  
• This enables operating with all-electric service in the portion of the corridor between San Francisco and San Jose, relegating the diesel fleet to where it belongs: not under the wire.
  
• Stops are restored throughout the corridor, increasing service frequencies especially in Silicon Valley where the 2004 arrival of the Baby Bullet decimated ridership at skipped stops that nevertheless have healthy numbers of nearby jobs and residents.
• Off-peak service is a subset of peak service, making for a regular and consistent half-hour "takt" throughout the entire day. This makes the timetable easy to use and memorize.
• The Gilroy branch is served by a cross-platform transfer in San Jose, reflecting the results of a recent survey of its customers that revealed that a one-seat ride was their lowest priority.
  

The Bad

• The Baby Bullet unfortunately survives as Express A, skipping perfectly worthy stops throughout Silicon Valley and tragically breaking the potential symmetry of the timetable. Express A should just be another Express B, giving evenly spaced 15-minute service from Redwood City to San Jose. This is very low hanging fruit that improves the timetable score from 115 to 118 points. The Baby Bullet pattern was a great idea for speeding up diesel runs, but in the new electric age, Caltrain should let it slip into history.
• The "South County Connector" remains as diesel rail service. There is an opportunity for  enormous savings (and better service quality for riders) from selling off the entire diesel fleet and operating the Gilroy branch with much more frequent luxury buses. Operating and maintaining an excessively large electric + diesel fleet and wasting capital funds on the expensive but dubious idea of a BEMU distracts Caltrain from its core mission. If one believes in the idea of a fiscal cliff, then it's obvious that rubber tires can help Caltrain's balance sheet until the high-speed rail project electrifies the south county corridor.
  

The Implausible

•  The proposed service pattern is built around a 75-minute all stops local trip between SF and SJ. This 75-minute figure is very impressive and would be a huge strength, if only it didn't border on the implausible. These are several issues with a 75-minute local run:
• the trains have to accelerate very aggressively, something the equipment is admittedly capable of, but ouch, that electricity bill! Operating cost will depend not just on usage but also peak load, and high acceleration makes the peaks worse.
  
• the timetable padding has to be shaved down significantly from today's comfortable margins
• the station dwell time has to come down to a crisp BART-like duration of just 30 seconds. Without level boarding, this is unlikely to work reliably in daily service. The boarding step arrangement, door spacing and interior circulation of the new EMUs is identical to the Bombardier diesel sets, so it's hard to believe they would board any faster, before even considering the possibility of a crew interventions for wheelchair users.
• There is nothing physically preventing a 75-minute trip, but if Caltrain can pull that off, what secret sauce of brief dwells have they been holding back from us all these years? Based on past operating practice, a more reasonable expectation would be an 86-minute trip. Let this serve as a prediction that Caltrain will find out the hard way that it really does have an urgent need for level boarding.

Taken together, there's a lot to like in this emerging service pattern, and a few tweaks can make it even more optimal. With freeway traffic getting steadily worse, the new service product will sell itself.

Leaping Off the Fiscal Cliff

One phrase we're going to hear a lot in the next couple of years is "fiscal cliff," a sudden disequilibrium between Caltrain's revenues and expenses caused by the withdrawal of the temporary federal subsidies instituted during the pandemic. The slow recovery of ridership, which until 2019 had funded ~70% of the railroad's operating expenses, is opening a $50 million/year hole in Caltrain's budget outlook through the rest of this decade, according to a draft Short Range Transit Plan (SRTP) recently submitted to the Metropolitan Transportation Commission (MTC).

The SRTP is a process that every four years requires each agency to project hypothetical near-term fiscal scenarios under a standard set of assumptions. Most interesting in Caltrain's draft is that the agency threw in a bonus scenario besides the prescribed hypothetical scenarios: the "Electrified Service scenario" a.k.a. Caltrain's actual plan.

This "Electrified Service scenario" makes zero effort to tackle operating costs, hiding behind a theory that Caltrain is inherently a high-fixed-cost operation, meaning that costs are not highly variable with the level of train service provided. All efforts are instead directed towards securing "funding opportunities," an approach that could very well succeed, as transit funding effectively grows on trees in California, no matter how inefficiently expended. Here are the scary numbers:

What if we blew up some long-held assumptions and attacked this fiscal cliff from the cost side?

Ditch Diesel Now and Go 100% Electric

Since time immemorial, the peninsula corridor electrification project has been sold as only a partial step towards electrification, anticipating that only 75% of the service would become electric with 25% remaining diesel, primarily to serve the non-electrified portion of the corridor south of San Jose. Operating a mixed fleet of diesel and electric trains blows up operating and maintenance costs, since many functions have to be duplicated (training, tools, spare parts, etc.). Revenue miles per vehicle are projected to drop by 10% when electrified service starts, which is a sure sign that your fleet is too big and isn't working hard enough.

How can Caltrain possibly operate with only the 19 EMU sets that will be delivered by 2024?

One certainly can't use all 19 in revenue service. Set one aside for maintenance downtime (grade crossing collisions will continue), and keep another two in reserve for timetable protection, essentially hot spares parked at each end of the line, crewed and ready to enter service at moment's notice to plug any delays during the peaks. That leaves just 16 sets to support a peak service level of six trains per hour per direction, a firm condition of Caltrain's funding agreement with the federal government.

That sounds downright impossible.

However, if you change the goals of a timetable to maximize equipment utilization, it turns out that it can be pulled off. Good service is just a side effect. Here is a new all-electric timetable that makes those shiny EMUs really earn their keep:

All EMU 6 tphpd
Score: 123 (relative to the benchmark score of 100 for the 2011 timetable)
Fleet: 16 EMU (zero diesel)
Utilization: 87% of train-minutes in revenue service

This is admittedly a slightly sporty timetable in that it requires aggressive 10-minute turns and a European level of padding of 7%, less than Caltrain is accustomed to dawdling with. The resulting risk of delay is mitigated by "protect" trains at each end of the line. There is also margin in the long station dwells (45 seconds) and the leisurely acceleration times built into the timetable, with power capped at only 2/3rds of the EMU's nominal rating.

The new EMUs would become highly productive assets by providing about 1.9 million revenue vehicle miles per year using just 133 cars, about 1.5x better utilization of these expensive depreciating capital assets than is currently contemplated.

The savings from disposing of the entire diesel fleet would be significant, and their residual resale value would only help Caltrain's balance sheet. The newer Baby Bullet fleet will have reached 20 years of revenue service, the minimum required by the FTA for federal funding assistance, so no penalties will arise from their early disposal. although its disposal would incur a small penalty reimbursement to the FTA since the equipment will not have reached its 25-year minimum useful life (according to FTA Circular 5010-1E, page IV-26.)

Divest the Gilroy Branch

One hitch: the overhead wire doesn't extend to Gilroy.

Gilroy service is a big weight on Caltrain's operational balance sheet because the ridership and revenue is minuscule compared to the high fixed cost of maintaining diesel service. Before the pandemic, ridership south of San Jose city limits (Blossom Hill) made up a negligible 0.8% of Caltrain's weekday ridership. South of Tamien was hardly better, at 1.2%. Until electrification is extended down to Blossom Hill (as it should be), it makes better sense to transfer this infrequent diesel service to an extended Capitol Corridor, with a direct cross-platform transfer to Caltrain in San Jose.

This can rid Caltrain of the entire diesel fleet, which is currently planned to remain at least 9 locomotives and 79 (!!) cars. It also frees Caltrain from another headache, having to comply with near-term diesel emissions mandates under consideration by the California Air Resources Board.

Reduce Conductor Over-staffing

Caltrain has too many assistant conductors. Assistant conductors are very expensive, costing about $15 million/year by FY25, about 1/3 of the operating deficit. Note this figure does not include conductors, only their assistants. The new EMUs relieve some of their duties, such as announcing station stops. The new fleet also has automatic passenger counters, giving precise real-time insights into passenger loads. While today's conductor staffing levels are determined by a formula from the number of cars, the formula should instead be revised to use recent passenger loads. This would ensure that all trains have a consistent staff/passenger ratio and that conductors have fair work loads.

Change the Operating Culture

With six electric trains per peak hour and at least 20-minute service at all stations, much better than is provided today, the conditions could be created for a robust recovery of ridership. Good service drives ridership, but if Caltrain is allowed to execute their mixed-fleet "Electrified Service scenario," as planned, we will barely achieve any service improvement as costs continue to spiral upwards.

Applying these cost-saving measures, Caltrain could close their operating deficit and erase any "fiscal cliff" without expending any energy to capture ever more "funding opportunities" to support entrenched and inefficient operating practices. The fleet does not need to grow, nor does the headcount. The operating culture needs to change: it's not enough to buy Swiss trains; you need to actually run them like the Swiss.

Capital Spending for Better Service

Wouldn't it be great if you could quantify the service benefit of capital improvements, to compare and prioritize them by how much better train service results?  We can, and using our handy Taktulator, we will. This service pattern evaluation tool was formulated around time-based service quality metrics. We use it to explore future improvements to the peninsula rail corridor.

Today's 2022 Timetable: 94 service points -- The current peak schedule with four diesel trains per hour features very generous padding and SF - SJ trip times ranging from 66 minutes (express) to 99 minutes (local). The less-than-100 score indicates that service quality has dropped since 2011 when there were five trains per peak hour. The Taktulator score is calibrated such that the 2011 Caltrain timetable scores exactly 100 points.

Caltrain's 2040 service vision foresees eight trains per peak hour per direction (not counting HSR). Let's start with a service frequency of 8 trains per hour-- except for the sake of exploring and quantifying the value of capital improvements, we'll start from a hypothetical case that will never happen: eight trains per hour of today's diesel service, making all local stops.

Hypothetical diesel all-stops local, 8 tph: Score = 109 service points (+16%) -- The doubling of hourly frequency improves the service score by 16%, despite each train being slower. The extra time riding an all-stops trains is more than offset by the much shorter wait time at the station. For example, maximum wait times in Belmont plummet from one hour to just 7.5 minutes. Unfortunately, this service pattern would take an unrealistic 32 trains to operate, because each train takes 94 minutes to go between SF and SJ. The hypothetical scenario still illustrates the magnitude of the effect of doubling frequency.

Add electrification: Score = 121 service points (+11%) -- Electrification is worth another +12 points relative to diesel, thanks to the shorter trip times that come from the higher acceleration capability of EMUs. Those savings accrue to a full ten minutes between SF and SJ for an all-stops local. Station dwell times are still booked at 45 seconds, a longer duration that reflects the lack of level boarding. Thanks to the faster trip times, the fleet requirement has dropped from 32 trains to 28 trains. Service speed saves money, not just on fleet size but also by increasing the hourly productivity of train crews (in terms of passenger-miles served).

Add Redwood City hub station: Score = 131 service points (+8%) -- If trains cannot pass each other, there is no room in such a frequent timetable for express service. A new four-track station at Redwood City, where express trains can overtake locals on opposite sides of the same station platform (so that passengers may transfer seamlessly between local and express) gives the best of both worlds: frequent service AND express service. For now, we'll assume this station has only two-track approaches, requiring trains to arrive and depart serially. In practice, this means every local must wait more than 5 minutes or the equivalent of two signal headways to let the express catch up before RWC and then pull ahead after RWC. The stopping patterns start to look like Caltrain's 2040 service vision.

Add Redwood City quadruple approach tracks: Score = 138 service points (+5%) -- If quadruple tracks are added approaching Redwood City from the north and south, then local and express trains can make parallel moves into and out of the hub station, removing the requirement for every local to wait there for five wasteful minutes. To unlock this benefit, the quadruple track overtake section needs to extend to one station on either side of RWC, so every local train can make productive use of those five minutes. In the Taktulator, we simulate this by having every local train stop at San Carlos and Atherton, which (despite its closure) stands in for a new Fair Oaks infill station at 5th Avenue. This suggests a hub station is about 1.7x more effective if it forms the center of a three-station quadruple track section. Having fully half your trains save five minutes is a huge service improvement!

Add level boarding: Score = 147 service points (+7%) -- Where electrification saved time in motion, level boarding saves time at rest by shaving 15 seconds of dwell time at each station, as step-free access smooths passenger boarding and alighting. Level boarding gives not only short dwell times but predictable dwell times (for example, wheelchairs don't take longer to board) so we can also tighten up the padding margin in the timetable, cut in this example from 12% to 7%. Interestingly, the end-to-end corridor times fall below a threshold that allows turning a train sooner, reducing fleet requirement from 28 to 24 trains. This isn't necessarily an effect of level boarding itself, and only illustrates that a series of small improvements can result in a discontinuous benefit when a certain threshold is reached.

Add SF Downtown Extension: Score = 250 service points (+70%) -- There are more jobs (over 100,000) located within a half mile of the Transbay Transit Center than there are jobs within a half mile of every other Caltrain station combined. This makes downtown SF a dominant node if added to the system, a fact that is reflected in our census-based weighting of available trips. No other improvement comes close.

Here is how these service improvements stack up against each other, plotted as the logarithm of the ratio of after/before scores, which gives you their relative impact. They can be constructed in a different order than imagined above, but the relative proportion of each improvement should remain approximately similar:

Bar graph of the relative service quality improvement of Caltrain capital projects

Here are some key takeaways:

1. Grade separation projects do not improve train service. Exceedingly rarely, they do prevent a train delay, something that is not captured in this analysis. On the basis of the time metrics of a typical trip, however, the service improvement of grade separations is ZERO. This should factor strongly into how many billions we are collectively willing to spend on them relative to the other capital improvements discussed here.
    
   
2. The benefits of electrification alone (without other improvements) are mediocre at best. On the basis of our time metrics, service quality is only improved by about 11% relative to an equivalent diesel scenario. Caltrain can't just finish the electrification project and call it good enough.
    
   
3. The Redwood City hub station now in the planning stages is surprisingly beneficial to service quality. While packaged and sold as a grade separation with a bonus of expanding the train station, it is hard to overstate the service quality benefit of the new hub station. Even as planned by Caltrain (with two-track approaches from the north and south) the new station produces nearly as much service improvement as the entire electrification project.
    
   
4. The Redwood City hub station as planned by Caltrain with two-track approaches is operationally ineffective. It can be juiced up to 1.7x more benefit to service quality by making it the center of a four-track overtake facility spanning just three stations: San Carlos, Redwood City and a new Fair Oaks infill station at 5th Ave. The southern portion of this four-track facility already exists today. Together with 4-track approaches, the Redwood City hub improves service quality by a greater proportion than the entire electrification project! That's why it is critical that planning for the Redwood City grade separations allow for four tracks throughout.
    
   
5. Level boarding provides over half the service quality improvement of electrification, and is likely to be a much cheaper capital investment. However, it makes sense to do it after the hub station.
    
   
6. The downtown extension in San Francisco will be a game changer for service quality. The transportation industrial complex knows this and will make us pay dearly for the DTX project. However, the additional billions for the PAX (Pennsylvania Avenue Extension, a city-desired grade separation) add absolutely nothing to service quality, and should never be allowed to be bundled with the DTX project. Every capital dollar should improve service quality.
    
   
7. The Redwood City hub station (with four tracks, not two!) is worth one fourth of the service benefit of the DTX. That means we should (a) not be shy about spending capital dollars to build it and (b) stop selling it as a grade separation, because that isn't the story here-- it should be about a new infill station, seamless transfers, and better service quality system-wide.
   

As always, the analysis provided here can be quibbled with and improved upon, and you are encouraged to "do your own research" by trying out your own service patterns in the Taktulator.

August 2021 Timetable Review

Caltrain was recently returned to more or less full service, with a timetable that is supposedly simpler (with a claim of just five stopping patterns) and features 104 trains per weekday, the most ever. Let's take a closer look using our handy taktulator, which assigns a timetable a score based on frequency and connectivity. The formulation of the service quality metrics underlying the scores is described here.

Caltrain's 2021 peak hour timetable achieves a score of only 96, meaning the service is slightly worse than the taktulator's baseline, the 2011 peak hour timetable, which a decade ago earned our reference score of 100.

Why so mediocre?

It's mostly in the padding. Caltrain service planners have evidently given up on trying to run a tight timetable while also dealing with the debilitating variability in station dwell times inflicted by the lack of level boarding. The right way to solve this problem was and remains to plan for and implement level boarding, a system upgrade that (on a per dollar basis) has even greater service benefits than electrification. The lazy way is what we see here: about 20% of extra padding is baked into the station-to-station run times, allowing a train to easily make up time and arrive "on time" in the event of a dwell time delay along the way. In the absence of a delay, trains can dawdle along even more slowly than the ancient diesel fleet could manage, and just sit at stations until the clock says it's time to go.

Back in 2005, a baby bullet express with five intermediate stops was timetabled at 59 minutes. In 2015, it was up to 61 minutes. Today, the same express runs in 66 minutes. This follows a pattern noted by Alon Levy on the deterioration of speed.

Another factor that explains the lower score is one fewer train per peak hour, resulting in longer intervals between trains. This helps with fleet size, where only 16 train sets (+2 spares) are needed to operate the 2021 timetable where 18 (+2) were needed before. Two more train sets are freed up for maintenance downtime, a vital bit of breathing room as Caltrain's older diesel fleet is breaking down more often. The fleet is well past its expiration date due to the multi-year delays in the electrification project.

Is it optimal?

Can a timetable be devised that uses no more than 16 (+2) train sets and scores better than 96? Why yes it can. Here is a Silicon Valley Express timetable that uses just 14 (+2) train sets with four trains per peak hour per direction, and scores 102.

Why is it better? First, it follows census patterns and puts the stops where they link the most residents and jobs, not where there is the most parking. It is more regular and has fewer gaps with long waits. While this does not figure into the service score, it makes far better utilization of the train fleet (83% of the time in revenue service, versus 70%). More efficient fleet utilization leads to fewer trains and fewer crews being needed to provide the same service, reducing labor and maintenance costs per passenger mile. All this is done without any magic: 15-minute equipment turns, comfy 40-second station dwells and a slightly less absurd padding level of 15%. There are zero overtakes, so fewer opportunities for cascading delays. Finally, this timetable is much simpler to understand for a rider, having just two service patterns.

One can only hope that despite this interim state of mediocrity, Caltrain will successfully implement its "moderate growth" service vision, which scores an impressive 240. Getting there will require reliable 30-second dwells for which level boarding is a must.

Credit to Richard Mlynarik who did the time-consuming part of this analysis.

Electric Timetable Contest

The coveted Takt Cup

Timetable planning has long been a staple of this blog, with the support of rapid prototyping tools like Richard Mlynarik's excellent Taktulator, a calculator for "Taktverkehr," the German term for clockface timetabling. While it may take a few minutes to learn how to use the tool, you can easily punch in a stopping pattern into the Taktulator to get an instant score, based on well-researched quality metrics and train performance calculations described here almost a decade ago. The service quality score is normalized so that the 2011 timetable, not much different from today's, earns 100 points.

Working back from its long term service vision, Caltrain has started planning for the near term timetable change that will occur with the start of electric service. Through a process of elimination, Caltrain has settled on two candidate service patterns, each with six trains per peak hour per direction, linked below in the Taktulator. You can verify that the resulting string line diagrams match extremely closely with the last couple of slides in Caltrain's presentation.

Two Zone with Express
Score: 123.3
Fleet: 13 EMU + 7 diesel

Distributed Skip Stop
Score: 124.1
Fleet: 13 EMU + 7 diesel
This timetable has a bit of a "can't get there from here" problem.

Can YOU beat those scores with a better concept?

Of course, scores depend on the assumptions you make. If you assume that the downtown extension is built into San Francisco Transbay, that all the diesels are replaced by EMUs, that dwell times are shortened by system-wide level boarding, that operating practices are reformed to allow better punctuality with less padding of the timetable, that terminal turn times are shortened to match foreign practice, and that a cross-platform transfer station is built in Redwood City with a short four-track section from just north of San Carlos into Redwood City (most of these contemplated in Caltrain's long-term planning), then you can set a sky-high score. In fact, using the Taktulator, you can even quantify the service benefit of each separate improvement. If we're allowed to dream, surely this is one of the most efficient:

Richard's Finest
Score: 230.2
Fleet: 16 EMU

Unfortunately, for the start of electric service in 2023, we'll have to settle for a bit less. There is no service to San Francisco Transbay, there is a fleet of 19 EMUs available of which you probably don't want to operate more than 17 at any given time, dwell times are still long (for simplicity, assume 45 seconds everywhere), timetable padding is ample (assume 10%), terminal turns are slow (assume 15 minutes), and there are no expanded stations or passing tracks. So, with those assumptions input into the Taktulator, can you beat Caltrain's score and win the coveted Takt Cup?

Please post your suggested Taktulator timetables and scores (and your supporting rationale) below in the comments. In your comment, use a clickable hyperlink, in the format <a href="your-taktulator-link">your timetable title<\a>, for brevity and clarity.

Here's my first entry for this contest, to kick things off:

Silicon Valley All Stop
Score: 126.9
Fleet: 17 EMU + 4 diesel

This improves on Caltrain's concept by admitting what census data and Caltrain's presentation tells us: all of Silicon Valley has enormous ridership potential, and running skip-stop express service south of Menlo Park is harmful to overall service quality. In short, the Baby Bullet is bad. This timetable also makes better use of the EMU fleet, as was intended when additional trains were ordered, by running 5 EMU + 1 diesel per hour per direction, instead of 4 EMU + 2 diesel.

Can you beat my score subject to the assumptions above?

Thinking Big in Redwood City

The architecture of Amsterdam Bijlmer
(photo by tataAnne) could represent
the future Redwood City station.

In a seamless transportation network that runs on a regular clockface schedule with timed, well-coordinated transfers, connecting nodes play a key role. Redwood City has natural potential as a connecting node, being located approximately at the midpoint of the peninsula rail corridor, serving as a logical transfer point between local and express trains, serving as the entry point to the peninsula from the future Dumbarton rail corridor, and being in of itself a significant destination with extensive connecting bus service and a willingness to grow.

With Redwood City currently renewing its interest in grade separations, it's important to think big and to re-imagine the station as a key node in the Bay Area's transportation network.

Start with a good timetable

Using our handy service pattern generator, let's see what we could do if we organized a blended system that made Redwood City a key transfer node. When you make a business plan, the first thing to be crystal clear about is: what is your product? In Caltrain's case, the timetable is the product, and all these stations and tracks should only be built as long as they contribute directly to delivering a quantifiably better timetable for the ordinary rider. Building a major new station in Redwood City isn't about trite superlatives like "Grand Central of the West," but simply about efficient and seamless coordination of timely and reliable ways to get from point A to point B.

Let's set some ground rules for our timetable:

• Caltrain expresses will operate every 10 minutes on a regular clockface schedule. A base 'takt' of 10 minutes reduces gracefully to 20 minutes or 30 minutes in the off-peak.
• In Silicon Valley, there will be no skip-stop service because the population and jobs are evenly sprawled. Every station in Silicon Valley needs to be served frequently, doing away with the ridership distortions induced by the Baby Bullet effect.
• In San Mateo county, where stop spacing is closer, slower local trains will operate every 20 minutes. These local trains will meet the express at Redwood City, before turning back north.
• Dumbarton service will operate every 20 minutes, meeting the express at Redwood City with little or no wait to transfer to trains on the peninsula corridor, before turning back towards the East Bay.
• Because the overall pattern repeats every 20 minutes, HSR will operate 3 trains per hour rather than the planned 4. Otherwise, there is a harmonic mismatch between the HSR frequency and the Caltrain frequency. 4 HSR trains per hour in a clockface timetable forces the base 'takt' to increase to 15 minutes, which is not desired.
• If we're going to make Redwood City a major node, it certainly rates HSR service, so we will create a new mid-peninsula stop for HSR.

This is the resulting timetable (see also additional data on service pattern), shown here for one hour in the southbound direction only (the northbound side is symmetrical). Colors denote the 10-minute Caltrain express, the San Mateo local, Dumbarton service, and HSR.

Notice the express arriving at Redwood City at 7:43 meets the Dumbarton train departing at 7:44, and the local arriving at Redwood City at 7:52 meets the next express at 7:53. Every ten minutes there is a cross-platform transfer, alternating between express-to-Dumbarton and local-to-express. Counting both directions, a cross-platform transfer occurs at Redwood City every five minutes!

Implicit in this timetable are a number of other capital improvements besides a new Redwood City station, such as overtake tracks in various locations along the corridor (highlighted in yellow in this view of the timetable... and while we're here, look how much less yellow is needed if HSR uses the Dumbarton corridor via Altamont Pass). It's important to remember that there is no formulation of the blended system that avoids the need for overtake tracks, unless one is willing to push slower trains into station sidings to sit for at least five minutes while a faster train catches up and pulls ahead. If you are a Caltrain rider, you should be wary of the cheapskates at the HSR authority who want to do this to your commute.

Deriving the functional requirements for the Redwood City node

To enable this timetable, we need the Redwood City station to have the following attributes:

1. Four platform tracks serving two 400-meter long island platforms to facilitate both northbound and southbound cross-platform transfers of very long, high-capacity trains.
    
2. Platforms centered on the best cross-town corridor, namely Broadway, for convenient access to and from local destinations on foot, by bike or scooter, by bus, or using the planned Broadway Streetcar.
    
3. A turnback track that enables certain Dumbarton corridor trains to originate and terminate in Redwood City, without fouling other train traffic, long enough for an EMU-8 train.
    
4. A turnback track that enables the San Mateo local to turn back in Redwood City, without fouling other train traffic, long enough for an EMU-8 train.
    
5. Elevated grade separation of all downtown Redwood City crossings, enabling free flow of pedestrians, bikes and vehicles under the rail corridor and including the re-connection of streets currently cut off by the existing configuration (e.g. Hopkins and James).
    
6. Bus facilities placed directly under the train platforms for seamless connections without the need for an umbrella. Same for an eventual Broadway Streetcar.
    
7. No mezzanine level. Mezzanines needlessly drive up the size and cost of stations, and impede and complicate vertical circulation. Street level can fulfill all the functions of a mezzanine, including ticket sales, wayfinding, waiting, retail, and dining.
    
8. The shortest and fastest possible vertical circulation (stairs, escalators, ramps, and elevators) using a U-shape viaduct cross section to avoid deep and vertical-space-wasting bridge structure. This helps with transferring quickly between the two island platforms, as would be needed for example to continue from the Dumbarton corridor south to Silicon Valley.

The footprint of such a station is not small. However, Redwood City has plentiful available railroad and transit district land, and the street level interface of such a station can be integrated into the city's street grid, opening up cross-corridor access and avoiding a wall effect. The aging Sequoia Station shopping center, with its wasteful surface parking, can be demolished and redeveloped to make room for an expanded station. Station parking can be moved underneath the approach structures, protected from the elements.

One possible station layout

An optimal station layout has four tracks, with the outer tracks for HSR and express commuter trains. The middle tracks are for commuter trains, and allow both northbound (Dumbarton) trains and southbound (San Mateo local) trains the opportunity to turn at Redwood City without impeding the flow of express traffic. The width of the structure is about 130 feet, as shown in the cross section below:

The northbound express track (Track 3) is tangent. The northbound island platform is 400 x 10 m. The center commuter tracks (Tracks 1 and 2) have curves that are not laid out in detail; this detail does not matter since any train that uses these tracks would slow and stop at Redwood City, using standard trackwork and turnouts. The southbound express track (Track 4) is the tricky one: it wows around the station, passing the southbound island platform on a 7500 m radius curve with approximately 1.5 inches of superelevation (not enough to matter for platform lateral tolerances). This track consists of a double reverse curve with six spiral transitions (tangent, spiral, curve, spiral, tangent, spiral, platform curve, spiral, tangent, spiral, curve, spiral, tangent). The curve is necessary to fit a pair of 400-meter island platforms (long enough to berth a double-length high-speed train) without bulldozing too much real estate.

Here is how this all fits (admittedly just barely) in downtown Redwood City:

The sacrificial victim is the Sequoia Station shopping center and associated surface parking crater, which can be redeveloped as part of the station complex with direct access from El Camino Real. Access for high-rise fire apparatus around the viaduct structure might also be a concern for the new condo buildings to the south, although this can be mitigated.

The station includes two pocket sidings to turn commuter trains. The siding south of the station can turn Caltrain locals at Redwood City, while the siding north of the station can turn Dumbarton service. Each siding is sized to store an eight-car EMU. Track center spacing is 15 feet throughout, and platform setback is 6 feet from track center. All viaducts are made from low-profile U-shaped sections that minimize the required height of the tracks and also double as sound walls, reducing the noise of up to 30 trains that would serve the station every peak hour.

Redwood City's slogan, "climate best by government test" would also become "transfer best" with timed, well-coordinated transfers to a variety of destinations. The impending start of designs for grade separations in Redwood City needs to factor in this future, and the city ought to think big.

Over-Promising on Electrification

Numerous recent Caltrain materials include the following quantitative claims (see slide at right) about the service benefits of the electrification project:

1. A baby bullet train making 5-6 stops will make the SF - SJ trip in 45 minutes, down from 60 minutes today.
    
2. A train making the SF - SJ trip in 60 minutes will be able to stop 13 times, up from 6 stops today.

Both of these claims are greatly inflated. They are easy to verify using a computer program known as a train performance calculator, which numerically integrates the differential equations of motion of a train based on the known characteristics of the track (vertical profile, curve, speed limits, station stops, etc.) and of the train (power, weight, tractive effort, drag, etc.) Physics and math can predict timetable performance quite accurately.

Myth #1: the 45-minute Baby Bullet express

Today's diesel performance
(pure run time, no padding)

Here is what a typical baby bullet run looks like today, with an MP-36 diesel locomotive, six Bombardier coaches, and a load of 600 passengers. There are five stops in this example, each lasting (very optimistically, as riders will attest) just 60 seconds. The pure run time from San Jose to San Francisco 4th and King is 52:22 under ideal conditions, without any margin or padding that is added to a real timetable; compare to the weekday northbound timetable at 64 to 67 minutes, or up to 25% longer (!) than the pure run time. Note that the weekday timetable has been extensively padded lately due to crowding; in 2012, the same run was timetabled at 59 minutes with 12% padding.

Tomorrow's EMU performance
(pure run time, no padding)

All other things being equal, let's substitute an EMU train for our slow diesel. The same run drops to 48:15, just four minutes quicker. This isn't surprising: baby bullet trains spend most of their time cruising near the speed limit, where the faster acceleration of EMUs doesn't provide a benefit. With all other things being equal (including crowding and long dwell times--why would electrification resolve these?) we can expect the timetable for our five-stop baby bullet to drop by the same four minutes, or 60 to 63 minutes. That is a full 15 to 18 minutes slower than claimed by Caltrain! Even if you remove the copious 5-8 minutes of extra padding present in today's timetable and compare to the 2012 timetable, we're still 10 minutes slower than claimed, at 55 minutes.

EMU performance at 110 mph
(pure run time, no padding)

How could you possibly get to 45 minutes? One approach is to raise the speed limit to 110 mph, which is planned in the long term but clearly outside of the scope of the electrification project. Changing only that variable, and slowing down as needed where curves limit the speed to below 110 mph, our EMU now makes the same San Jose to San Francisco run in 41:32, almost seven minutes faster. However, we're still 7 to 10 minutes slower than Caltrain's 45-minute claim, or 2 minutes slower when using 12% padding. Again, the reasons for having such enormous amounts of timetable padding will not suddenly disappear after electrification!

The best way to get there is with level boarding, which alleviates Caltrain's crippling dwell time problem. Level boarding has two benefits: the primary benefit is in the form of reduced dwell time during each stop, and the secondary benefit is in the smaller amount of timetable padding that is needed, thanks to the improved schedule adherence that is possible when the occasional wheelchair lift deployment no longer threatens to inject random three-minute delays. Padding could conceivably be cut to 7%, and dwell time to 30 seconds. No new simulation runs are required-- our five-stop 79 mph EMU makes it in (48:15 - 2:30)*1.07 = 49 minutes on the timetable; the 110 mph EMU makes it in (41:32 - 2:30)*1.07 = 42 minutes.

Caltrain's claim of a 45-minute baby bullet is readily attainable only after three major improvements are made. These are not included in the scope of the electrification project and are currently unfunded:

1. Conversion of the baby bullet fleet from diesel to EMU
2. Implementation of system-wide level boarding
3. Curve realignment, track upgrades and grade crossing safety upgrades for 110 mph

To promise a 45-minute baby bullet run in the short term is at best misleading and at worst a flat-out lie. Once the electrification project is complete, we can expect approximately zero improvement in baby bullet performance, with timetabled runs in the range of 64 to 67 minutes. If the initial slight increase in capacity of the electrification project relieves crowding (but will it, enough to offset the performance loss from dragging a seventh Bombardier car?) then we could return to the 2012 timetable performance of 59 minutes.

Myth #2: the one-hour, 13-stop limited

Let us assume for the moment that padding returns to the 2012 level of about 12%. Assuming 60-second dwells and a 79 mph speed limit, how many intermediate stops can a limited train make between San Jose and San Francisco before the timetable hits one hour?  Subtracting 12% pad from one hour, we need to make a pure run time of 53:34.

With today's diesel bullet performance, Caltrain's claim of six stops in one hour checks out reasonably closely at 54:57 or just over one hour including padding, i.e. close enough. Let's change the assumptions, one by one:

Simulation Case	Pure Run Time	Timetable
Case A, Diesel, dwell 60, 6 stops, 12% pad	0:54:57	1:01:33
Case B, EMU, dwell 60, 6 stops, 12% pad	0:50:10	0:56:11
Case C, EMU, dwell 60, 7 stops, 12% pad	0:52:04	0:58:19
Case D, EMU, dwell 60, 8 stops, 12% pad	0:53:58	1:00:27
Case E, EMU, dwell 30, 8 stops, 7% pad (level boarding)	0:49:58	0:53:28
Case F, EMU, dwell 30, 9 stops, 7% pad (level boarding)	0:51:22	0:54:58
Case G, EMU, dwell 30, 10 stops, 7% pad (level boarding)	0:52:46	0:56:28
Case H, EMU, dwell 30, 11 stops, 7% pad (level boarding)	0:54:10	0:57:57
Case I, EMU, dwell 30, 12 stops, 7% pad (level boarding)	0:55:34	0:59:27
Case J, EMU, dwell 30, 13 stops, 7% pad (level boarding)	0:56:58	1:00:57
Case K, EMU, dwell 30, 13 stops, 7% pad (level boarding), 110 mph	0:53:08	0:56:51

Simulation Case K
(pure run time, no padding)

Case D shows that the maximum number of stops permissible under post-electrification conditions is at most 8, just two more stops than today, and not 13 as claimed by Caltrain. Only after level boarding does the number of stops increase to 13 as shown by Case J, but once again, level boarding is not included in the scope of the basic electrification project. Case K illustrates the diminishing returns from increasing the speed limit to 110 mph; the more stops a train makes, the less benefit there is from the higher allowable speed. Case K (see diagram at right) shows the train almost constantly accelerating and braking, which is not how one would choose to operate given the cost of electricity in the real world.

The takeaway message to Caltrain is this: don't over-promise and under-deliver on the modernization project. Your electrification project reduces time in motion and establishes a foundation for further improvements, but is not sufficient by itself. To deliver the service benefits promised in your public presentations, you absolutely need level boarding to reduce time at rest.

(do I sound like a broken record?)

Frequent Trains Off Peak

After electrification, Caltrain aspires to operate off-peak service at 2 or 3 trains per hour, instead of the current 1 train per hour. All-local service at 3 trains per hour works out to a fleet requirement of 12 trains in service, far less than needed for rush hour, but still racking up almost 300 train-miles per hour, or triple today's rate. That sort of service level will not be cheap to operate, unless two conditions are met to reduce operating and maintenance costs:

1) Operate Short Trains Off Peak

Shorter trains off-peak reduce maintenance costs by putting less wear and tear on the vehicles and track. The same revenue train-miles can be offered with fewer car-miles. The more off-peak service is provided, the greater the savings: at 3 trains per hour, operating 4-car EMUs instead of full-length 8-car EMUs off-peak results in a huge reduction of 25% fewer weekday car-miles.

Operating and vehicle maintenance
costs of US commuter rail, per car mile

Just how big are the savings? Typical commuter rail costs are available from the FTA's National Transit Database. The operating and vehicle maintenance costs for Caltrain and selected commuter rail operators are shown at right for the year 2015, normalized by the total number of car-miles operated. Some on this list (Metro North, LIRR, SEPTA and New Jersey Transit) operate sizable fleets of EMUs, but their maintenance costs are not significantly out-of-family with Caltrain; therefore, it's fair to assume that maintenance costs will not materially change after electrification. Since the FTA maintenance totals are not broken out by fixed and variable costs, we will conservatively assume that the variable cost (which scales directly with the number of car-miles operated) accounts for half of the vehicle maintenance cost. Squinting at the chart, let's estimate this variable cost at $2 per car-mile.

When you operate 12 hours of off-peak service at 300 train-miles per hour, the variable cost of vehicle maintenance racks up at 12 hours/day * 300 train-miles / hour * 8 cars/train * $2/car-mile = $58k/day. By reducing off-peak train length to 4 cars/train, the savings are half of this, or $29k/day. The savings from shorter trains accrue not just on weekdays but on weekends too, yielding annual savings of roughly $10 million.

Then you might want to factor in energy cost savings. Each car weighs about 60 tons loaded, and is accelerated to about 60 mph between two typical stops. The electricity consumed to accelerate is re-generated into the grid while braking for the next stop, with a round-trip efficiency likely in the neighborhood of 80%. That means overcoming the inertia of one car for one stop (neglecting drag) takes 4 MJ of electricity, or 1.2 kWh in more familiar units. At typical electricity rates of 12 cents/kWh, that's just $0.14/car/stop. Multiplying it up, $0.14/car/stop * 20 stops * 3 trains/hour/direction * 2 directions * 12 hours/day * 8 cars/train = $1600/day.  (Note that drag will significantly increase this figure, but can be neglected for this estimate because the drag of a 4-car train is similar to that of an 8-car train.) By reducing off-peak train length to 4 cars/train, the savings are $800/day. At less than $300k per year, this is just a rounding error compared to the vehicle maintenance, and can be ignored.

The Scharfenberg automatic coupler,
nicknamed "Schaku," linking up two
short EMUs (click for movie)

Offsetting these savings are the costs of making and breaking train formations several times per day, since the entire fleet needs to be available for morning and evening peak service with full length 8-car EMUs. Traditionally, this is a cumbersome operation that involves expensive and specialized labor, with ground crews stepping onto the tracks to connect pneumatic hoses and high-voltage cables. Caltrain is breaking with tradition by using a neat technological trick: the couplers on each end of the new EMUs are fully automatic Schakus, making mechanical, pneumatic and electrical connections in a matter of seconds at the touch of a button in the train cab. Barring any union rules relating to craft distinctions, making and breaking trains can be performed by train crews with zero additional labor cost.

2) Operate With One Conductor

Labor accounts for about two thirds of operating costs in typical commuter rail systems. Operating costs are strongly driven by train crew size. Minimum crew size is constrained by union rules that govern how many conductors must work on each train. Currently, the minimum crew size (dictated by Rule 11 of the agreement with the UTU) is 1 engineer, 1 conductor and 1 assistant conductor for trains up to seven cars, with a second assistant conductor required for an 8-car train or longer.

When contemplating a tripling of off-peak service, the cost of this minimum staffing level becomes prohibitive. Conductors are paid about $40/hour, and assistant conductors about $35/hour. Including benefits and other employee costs, the overall cost of these employees is easily double these figures. Additionally, conductors typically spend about half their shift time on board a revenue-producing train, so the necessary staffing levels are roughly double the number of trains in service. We saw earlier that it takes a fleet of 12 trains to operate off-peak service at 3 trains per hour per direction; staffing an assistant conductor on these trains would cost $70/hour/conductor * 1 conductor/train * 2 hours/(revenue hour) * 12 trains * 12 (revenue hours)/day = $20k/day. Again this is big money: the savings from removing the assistant conductor and going to one-conductor operation accrue not just on off-peak weekdays but on weekends too, yielding annual savings of roughly $7 million.

How do you sell this lower staffing level to the union?

1. EMUs can relieve conductors of some of their workload, after automation of many of their traditional roles (such as stop announcements, door and lift operation, or signal aspect acknowledgement). Fare verification (proof of payment) could even become a separate role carried out by roving fare inspectors.
2. Conductor staffing levels or pay rates can be renegotiated on the basis of actual ridership, instead of the number of train cars, since the new EMUs will have automatic passenger counters that collect detailed and accurate passenger ridership statistics.
3. Most importantly, the total amount of work for UTU-represented employees would increase, since one-conductor operation would enable a tripling of off-peak service, resulting in 1.5 times more labor hours even after cutting conductors staffing levels in half.

It isn't a stretch to envision Caltrain and the UTU re-negotiating the labor agreement to allow just one conductor on four-car off-peak trains; there is room for a compromise that can benefit everyone.

Future Fleet Implications

If you zoomed way, way, into Caltrain's
exterior paint scheme concepts,
the Schaku was plain to see

Caltrain's initial fleet of sixteen six-car EMUs (total 96 cars) will not have the ability to split into shorter formations, but once the option for 96 additional cars (total 192 cars) is exercised, and all trains are extended to their intended length of eight cars, the practice becomes not only possible, but necessary for providing frequent off-peak service.

The fleet needs to operate two service patterns:

1. peaks at 6 trains per hour with a fleet of 8-car EMUs
2. off-peak at 3 trains per hour with a fleet of 4-car EMUs

To support both service patterns using the planned fleet size of 192 cars (including a rather large spares ratio, to withstand regular grade crossing collisions), the optimal fleet configuration is probably something close to:

• 16 4-car EMUs for off-peak service, each with one bike car and one bathroom car, that can be coupled in pairs during peak hour service to form eight trains with eight cars each.
• 16 8-car EMUs for peak service, lengthened from the base order

This results in the following order breakdown for the 96 additional option cars:

• 32 passenger cars for CalMod 1.1
• 32 cab cars, for 4-car EMUs
• 16 bathroom cars (powered), for 4-car EMUs
• 16 bike cars (unpowered), for 4-car EMUs

This EMU fleet configuration enables 20-minute off-peak service frequency for at least $17 million/year cheaper operating and maintenance cost than would otherwise be achieved with a uniform fleet of all 8-car trains. That's a large amount, easily over 10% of Caltrain's current annual operating budget. Considering that Caltrain struggles every year to scrape together enough operating funds, a stronger way of stating it is that without 4-car EMUs and one-conductor train crews, Caltrain will simply not have the financial means to provide 20-minute off-peak service frequency.