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.

Diridon Delusions

San Jose is striving to redesign and expand its Cahill Street station, named for the (still living) former Santa Clara County board of supervisors chair Rod Diridon, to meet the needs of future rail service including BART and high-speed rail. The station's context was discussed here in 2017.

The process led by the Joint Policy Advisory Board, made up of representatives from the city and relevant transportation agencies, has now reached the key juncture of presenting a small number of alternatives to the public. Before we dig into this, let's pause to consider an alternate plan.

The HSR Environmentally Cleared Project

This design is already
environmentally cleared.

The California High-Speed Rail Authority, as part of its San Jose to Merced project, has already obtained full federal and state environmental clearance to build the simple Diridon station concept shown at right. This plan adds a couple of overpass mezzanines above the existing platforms, and rebuilds two of these platforms for compatibility with high-speed trains, using the newly established standard height of 48 inches above top-of-rail and lateral offset of 73 inches from the track center. The 48" x 73" platform standard was agreed in June 2023 between the Authority, the FRA, and other prospective high-speed rail operators such as Brightline West. Due to budget pressures, the HSR project took a rather minimalist approach to this station, electing to build it at grade within the footprint of the existing facility, but pledged to work harmoniously with other agencies on more ambitious concepts. Think of it as a minimum viable product that has already cleared CEQA and NEPA, before we turn to what is now brewing for San Jose.

The Diridon JPAB Alternatives

In any public alternative evaluation process, it is important to carry a sacrificial alternative. This serves the same role as an unlikable character in a movie, whose demise is heavily foreshadowed and brings relief to the viewer when it occurs. The sacrificial alternative can be eliminated in an overt display of due diligence, reassuring the public that the authorities are being thrifty and mindful of the interests of riders and taxpayers. In this case, the "stacked" alternative seems to serve this purpose, and warrants no further discussion because it will shortly be eliminated.

Note similarity of elevated and at-grade options.

This leaves a choice between two alternatives known as "at grade" and "elevated," actually a distinction without much difference. Both designs are driven by an overarching requirement to create an expansive concourse level below the tracks and platforms, purporting to imitate grand European train stations but far more likely (this is America!) replicating the airport experience for train passengers. Early architectural renderings show this as an open and airy space resembling an Apple Store, paying no heed to the fact that the sky will be completely obstructed by tracks and platforms built on a dense forest of beefy concrete columns. No matter how pretty the architects try to make it, this will be a heavy elevated structure built on alluvial soils near seismically active faults. The light-filled and soaring station canopy will be enjoyed by nobody for any length of time, since all waiting areas will be in the basement.

Things to Watch For

The effectiveness of a station modernization project should be measured by its operational efficiency. The primary focus should be on shaving seconds off travel times, to include:

• Removing slow zones in the station approaches. On the north side, this means removing the CEMOF double reverse curve, a self-inflicted obstacle added in 2005 that limits all trains to 40 mph over a mile before the station. Main tracks MT2 and MT3 should be restored to their former alignment on the west side of the maintenance facility, with a flatter curve allowing trains to pass the facility at higher speeds. On the south side, this means greatly increasing the speed limit between San Jose and Tamien, currently just 35 mph, and providing at least two electrified tracks.
   
  
• Re-configuring the layout of north and south station interlockings (a.k.a. "station throats") to enable swift and parallel train moves into and out of the station, on turnouts rated for much higher speeds than 15 mph of the current layout. Nobody in Europe or Asia would accept a train crawling slowly along a platform while dinging insistently; trains arrive and depart swiftly and quietly.
  
  
• Ensuring that all Caltrain traffic will shoot through on just two platform tracks and one island platform. Despite the "south terminal" school of thought still prevalent at Caltrain headquarters, San Jose Diridon should become just another intermediate stop on the way to further destinations in the greatly under-served but densely populated southern parts of the city, which the BART-fixated county agency seems to have completely forgotten about. A great way to sell this extension would be as a "South San Jose to BART Regional Connector Project." Cutting Caltrain's footprint to just two tracks and one island platform will free up ample space for other operators.
  
  
• Providing excellent vertical circulation, which means short vertical circulation. This is one benefit of putting the concourse under the tracks: people are shorter than trains. Architects should resist the urge to make the ceilings in the passenger concourse vault too high because this needlessly extends the reach of stairs, escalators and elevators. Likewise, structural engineers should resist the urge to put the tracks on top of enormous concrete box girders. The early concept renderings show 15-foot ceilings with 9-foot structure depth, while 12-foot ceilings and 3-foot structure depth (using through-girders) would bring the entire structure 9 feet down. This saves every single passenger ten seconds of vertical transport, worth an hour per year for each commuter! Don't go for drama, go for ruthless efficiency: form must follow function.
   
  
• Providing a straight-shot escalator / elevator ride from the north end of the Caltrain platform to the west end of the underground BART platform. This simple shortest-path connection avoids a long and circuitous walking detour through the main BART entrance, located outside and east of the station footprint. Please don't let agency turf lead to lengthy and confusing transfers.
  

The unifying theme here is to save passengers time, whether on the train or in the station. Every second of the San Jose travel experience matters. A counter-intuitive fact about high-speed rail is that the best way to save time is to relentlessly focus on speeding up the slowest bits, like station approaches and escalator rides. In terms of capital costs, those are by far the cheapest seconds to save. California has already committed to the enormous expense of building a 220 mph system, and San Jose is not the place to wastefully undo those hard-won time savings.

If operational efficiencies are not realized in San Jose, and the opportunity to bring the station into the 21st century is not captured, then we'll end up with a new multi-billion dollar train basement that does little to improve regional transportation.