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.

Level Boarding is Legal in California

Arrow level boarding platforms
at San Bernardino, CA

Comments to old posts on this blog are stored in a moderation queue that your author doesn't visit often enough. Over a year ago, commenter jpk122s discovered quite a gem: an official resolution by the CPUC (California Public Utility Commission) that level boarding station platforms are not bound by General Order No. 26-D section 3.4. This means it's nerd time.

Some California Background

The CPUC regulates all railroads in California, including their clearance dimensions under General Order 26-D. This regulation, originally published in 1948, requires all mainline train platforms to be no higher than 8 inches above top of rail per section 3.3. If you want to build a station platform higher than 8 inches, it needs to be set back at least 7'6" from the track center line per section 3.4. This requirement is deeply inscribed into the built environment of train stations around California, including Caltrain's.

• The taller platforms used for boarding passengers with reduced mobility, known as "mini-highs" and cluttering the north end of most Caltrain station platforms with ramps and railings (see diagram below), must be set back at least 7'6" per section 3.4. This is quite far from the track, requiring the use of bridge plates to cross the wide (~3 foot) gap between the mini-high and the train.
  
• The 48" level boarding platforms used by SMART (in Sonoma and Marin counties) are closer than section 3.4 requires, but as mitigation, a set of gauntlet tracks allows freight trains to stay clear.
• The 23.5" (ish) level boarding platforms used by Sprinter (Oceanside to Escondido) are closer than section 3.4 requires, but as mitigation, they have folding edges that tilt up and out of the way of freight trains that pass during the night.

Current Caltrain platform standards

These examples are all Rube Goldberg solutions that are expensive, clunky and inconvenient – especially when considering that nothing physically precludes freight trains operating past high platforms, as is common practice on the east coast.

Then, along came the San Bernardino County Transportation Authority, with a request for an exemption from section 3.4.

Level Boading for Arrow

Arrow is the brand name for a new passenger rail service linking San Bernardino to Redlands. This service uses Stadler FLIRT diesel multiple units, of a standard vehicle design sold in more than 2500 copies around the world. The platforms are built for level boarding at 23.5" to comply with the accessibility requirements of the Americans with Disabilities Act (ADA). Rather than contrive a new technical solution to comply with GO 26-D section 3.4, the parent agency did something unusual: they asked for an exemption.

The May 5th, 2022 resolution adopted by the CPUC, an agency known for its conservatism and dogged focus on safety, was surprising: "The RSD [Rail Safety Division] has determined that an exemption from General Order 26-D, Section 3.4 is not necessary since it is preempted by the federal Americans with Disabilities Act (ADA)." Section 3.4 (a state regulation enacted in 1948) is preempted by the ADA (a federal law enacted in 1990). The resolution continues:

General Order 26-D, Section 3.4, sets forth a minimum clearance requirement for station platforms. However, this provision of General Order 26-D is preempted by the ADA, which requires a different platform height and distance from track center line to accommodate the introduction of the Multi Unit (MU) equipment– and thus, results in a smaller clearance area – than what is set forth in General Order 26-D, Section 3.4.

Interestingly, the freight railroads that usually complain about the slightest infringements to their operating environment did not comment on the resolution before it was adopted by the CPUC.

Implications for Caltrain Level Boarding

Perhaps Caltrain already knew this all along, but this CPUC order implicitly relieves one of the key regulatory constraints to platform heights and level boarding, discussed numerous times in the past 15 years of this blog. It turns out that no waiver of GO 26-D section 3.4 is ever needed.

It may take a year or two before Caltrain finds out the hard way why they need level boarding, but this is a positive development. For that, we have the San Bernardino County Transportation Authority to thank.