Caltrain's Plan for Level Boarding

Some good news: Caltrain is working on a level boarding plan, as documents requested under the Public Records Act attest. Their "Level Boarding Roadmap: Technical Task Force Platform Report" dated April 2024 is a reasonably well-written document that discusses how the system might be converted to level boarding using the European 550 mm platform standard. After reading it, three questions arise:

1. Why are 48" level boarding platforms never discussed? The roadmap takes for granted that Caltrain's solution is 550 mm (22") platforms. It mentions "Caltrain EMUs have doors (...) at the mid-level (currently these doors are plugged)" and never again mentions how these doors got there, what else might be done with them, or why it shouldn't. While every solution has pros and cons, how is such a fundamental decision of system architecture presented with no context as a done deal, without the slightest technical rationale or public discussion?
    
   
2. Why is the preferred solution allowed to violate HSR specifications?
   
   22" platforms are discussed with two lateral offset alternatives: 64" (preserving today's platform offsets) and 68". The safety argument presented in favor of a 64" offset does not contemplate that such platforms would encroach into the high-speed rail vehicle body dynamic envelope, and that wide-body HSR cars would extend over the platform. These issues are shown in the precisely scaled graphic at right, using dimensions from the HSR vehicle RFP. Neither of these conditions seems safe and neither is addressed in the hazard analysis, unless an unstated assumption is being made that the high-speed rail project should fix Caltrain platform design errors at the public's expense.
    
   
3. Why was this work not done ten years ago, before EMU procurement? There is no value added by testing platform mockups with a real EMU as done in the report, versus testing with a plywood vehicle mockup. Everything discussed in Caltrain's report was known ten years ago and the Stadler EMU fleet could have been delivered with a platform interface solution for level boarding at 22" had Caltrain specified one. Now, we're stuck with a retrofit situation, but better late than never.

The next steps discussed in Caltrain's report are good ones, and should be expedited. Specifically, developing a technical solution for an automatic step arrangement compatible with both 8" and 22" platforms is of the highest urgency. ("Funding a prototype for an estimated $3M lowers technical risk and also shortens the timeframe to begin fleet implementation should funding become available.") This small investment is among the most important and valuable projects that Caltrain should undertake immediately.

A bit over a month of electric service has made it abundantly clear that dwell times are long and on-time performance is systematically poor due to the rosy performance assumptions baked into Caltrain's timetable. The trains are fast, but much of their performance is wasted on long dwells. Level boarding can't come soon enough.

Another Path to Level Boarding

A complication in Caltrain's coming transition to level boarding is found in the train's bathroom, an amenity that requires equal access for passengers with reduced mobility under ADA regulations. During the procurement and design phase of the EMUs, the original plan was to fit in-vehicle wheelchair lifts to enable passengers with reduced mobility to move between the lower level and mid-level, for level boarding compatibility with future high-speed rail platforms (48" above rail, 73" from track center) and to enable bathroom access regardless of boarding level.

This plan fell apart because of practical considerations of cost and vehicle packaging: the bulky 800-pound capacity lifts would have impeded passenger flows in the lower-level vestibules, without providing any value until some distant future where Caltrain would need to dock at high-level platforms in stations shared with high-speed rail. Even then, the lifts would have been required indefinitely, to provide equal access to the bathroom on the lower level. The idea was so unappetizing that it was scrapped, and Caltrain has since focused its nebulous level-boarding strategy around European-like 550 mm platforms.

The EMUs are nevertheless designed for future conversion to high platforms. A different solution is available that would facilitate a transition to 48" platforms: a new single-level, high-floor bathroom car that would take the eighth slot in the consist. The EMUs were always planned to be eight cars long, as their numbering attests by skipping from 1, 2, 3 to 5, 6. Missing car number 4 could have this configuration, as modified from a Stadler drawing:

The new high-floor bathroom car would triple bathroom capacity of the trainset from one to three bathrooms, provide 60 seats with up to six wheelchair spaces, and enable a gradual transition to 48" level boarding using car-borne wheelchair lifts (such as the FRA and ADA compliant PowerLift by Rincon) to board passengers with reduced mobility from legacy 8" platforms, without the need for precise positioning of train doors relative to mini-high platforms. Once the transition to level boarding is completed, these lifts could be removed.

With the bridge plates already engineered for the EMUs (shown in photo at right but not fitted to the fleet as delivered) passengers with reduced mobility could board step-free without any crew assistance, greatly improving the predictability of dwell times and thereby increasing train speeds and corridor capacity.

The transition to high platforms would then entail the following steps:

• Extend all platforms and yards to support eight-car trains
• Incorporate new single-level bathroom cars to all trains
• Commission high level doors and install bridge plates
• Build new 48" platforms!
  

High platforms have the advantage of compatibility with high-speed rail, enabling any train to dock at any platform as needed and making optimal use of future corridor and station capacity. They allow high-speed trains to make stops at important places like Redwood City or Palo Alto with zero additional infrastructure. They allow Caltrain to operate like BART, with brief and predictable station dwell times, something that remains out of reach today even as our swift and modern EMUs must wait for extended periods at low platforms, in the manner of a Ferrari driven on a rutted dirt road.

Cars on the Tracks

Cars turning off from a grade crossing onto the tracks are a perennial problem for Caltrain, often resulting in multi-hour cascading delays or worse, dangerous collisions. The statistics are shocking: from 2020 through 2023, there were 183 recorded incidents of "vehicle track incursions," of which more than half occurred at just five crossings as shown in the Caltrain bar chart at right.

Caltrain has tried mightily to take measures against this human error. It's useful to view these attempts through a risk management lens: the risk is the product of the probability of a vehicle entering the tracks, multiplied by its consequence.

Reducing Probability

We can do a little bit of Street View tourism to see what solutions have been attempted so far to reduce the probability of a vehicle track incursion:

	Paint stripes give visual feedback, but such road markings are often not observed by the sort of driver who might not see that they are turning onto tracks.
	Reflectors and Botts Dots keep a low profile to fit under passing trains, while giving visual and steering wheel feedback. In the gauge, they get beat up by equipment dragging under freight trains. This example is at Castro Street in Mountain View.
	Rumble strips, similar to above solution, at Mission Bay Drive in San Francisco.
	Solar reflectors go one step further by lightning up at night. The small solar cell at the top charges a battery that powers red LED lights when it is dark. This example is at 16th Street in San Francisco.
	Speed bumps provide slightly more steering wheel feedback. This example is at Mission Bay Drive in San Francisco.

All of these measures are probably effective to some extent, but they won't stop a vision-impaired or inebriated or inexperienced driver, especially when they are mindlessly following GPS directions to turn onto a street that immediately parallels the tracks, a common feature of the grade crossings with the highest incidence of vehicle track incursions.

Reducing Consequence

Before we can discuss reducing the consequence of a vehicle track incursion, we need to acknowledge just what the consequence is: at a minimum, the vehicle becomes stranded on the tracks, requiring extrication by a tow truck. At worst, there is a dangerous collision with a train.

Most vehicles will end up high-centered if they blunder onto the tracks because the rail is 7" 5/16 tall and the center of concrete ties dips lower, resulting in easily 9" of height difference between the surface of the ties and the top of the rail. This height exceeds the ground clearance of most SUVs. Once high-centered, a vehicle with open differentials (i.e., not-Jeep) loses traction and becomes stranded. The driver is unable to correct their mistake, and when they try, they often just make it worse by driving further onto the tracks.

Currently, Caltrain applies no mitigation to this consequence. Their entire risk mitigation approach to vehicle track incursions relies on prevention, by reducing the probability while accepting the consequence that a stranding is inevitable. It is not!

Anti-trespass panels in New York, on Metro North.
Photo by Daniel Case.

Anti-trespass panels can mitigate the consequence of a vehicle track incursion through two mechanisms: 

1) very strong vibratory feedback that the vehicle has departed the road, likely to induce brake application on a reflexive basis and avoiding a deeper incursion.

2) reduced height difference between the rail and surrounding surfaces, enabling a vehicle with low ground clearance to maneuver without becoming high-centered. The driver can self-extricate the vehicle.

While these rubber panels are primarily intended to prevent pedestrian trespassing, they would likely also work for cars if laid down for about 30 feet beyond the edge of a crossing. They are a passive solution with low operating cost, certainly a much more effective mitigation than CCTV or intrusion sensors with alerts integrated into the signalling system. All these expensive and technology-heavy solutions may prevent a collision, but do nothing about the need for a tow truck or the resulting service disruption. This makes anti-trespass panels an ideal solution that best addresses the need of Caltrain riders to arrive on time.

The south side of Churchill Avenue in Palo Alto would make an excellent location for a pilot installation.

September 2024 Open Thread

Electric service starts this weekend.  The blog comment system stopped working on the August open thread, so let's try this instead?

August 2024 Open Thread

Open thread time! Feel free to jump into the comments below.

• Driving like a grandma: electric service started on August 11th. Initially and until September 21st, EMUs operate on the current diesel timetable, for which they are grossly overpowered. Therefore, trips are sedate, and the full benefits of electrification are yet to be realized. We can't wait!!!
   
  
• Wasted dwell time: per FRA safety regulations, doors may only unlock and be opened when the train is at a complete stop. The drop step mechanism that deploys from below each door must obviously be fully deployed for the door to be unlocked and opened. Unfortunately, the software that controls this operation also appears to require that the train be at a complete stop for the drop step mechanism to operate. The result is eight to ten seconds wasted by the cycle time of the step mechanism (see video) which becomes a series contributor to dwell time. For an all-stops local, that waste is worth a full three minutes of run time. A typical Caltrain user travels for about 20 miles, let's say seven stops each way-- that's 140 seconds per day wasted. Multiply by 250 work days, and a full-time commuter will waste about ten hours waiting for those silly steps.
  
  
  This can be fixed in software. As seen in the timeline graphic, allowing the step to deploy and retract while the train is in motion would remove this wasted dwell time. The step mechanism can be cleared to move only when the train is moving slower than 5 mph, and since the step itself does not extend over the platform (it reaches only 63.5 inches from vehicle center line when fully extended) there can be no hazard to passengers. We spent a lot of money to save 25 minutes of SF-SJ run time, so please, let's not piss away 3 minutes because of overly conservative door sequencing software.
  
  
• Spares ratio: full electric service from September 21st onward requires at least 14 trains, not including spares. As of August 10th, twelve have been documented via photographs and video as having arrived in California (see tracking spreadsheet). One of them suffered a collision and was returned to the factory for repairs last March, leaving 11 known to be in California today. Two more (most likely 313/314 and 315/316) are due in early September. Peak service periods, when all 14 EMU sets are needed in service, can be protected with diesels if allocated exclusively to express services where they can sort of keep up, until further EMUs are delivered to increase the spares ratio above zero.
   
  
• Costly fender bender: Early this year, EMU 311/312 suffered a sideswipe collision at the CEMOF yard and was sent back to Salt Lake City for repairs. Two cars were damaged (see photo) and Stadler had to fly in welders from Switzerland to assess structural integrity and the cost of repairs. Aluminum isn't like steel, you can't just take hammers and a blowtorch to fix collision damage. The manufacturer's recommendation is said to have been full replacement, a multi-million dollar proposition.
   
• Wheel flat spots continue: detracting from the high quality of the new electric trains, there seems to be a continuing fleet-wide issue where all non-powered axles are prone to developing flat spots. The affected axles are located on the bike cars, and under the end cabs; once you hear this pattern, you can't un-hear it. As utilization ramps up, and especially when the next rainy season hits, let's hope this issue doesn't devolve into an epidemic of sidelined trains.

Feel free to comment on this or anything below.