Thursday, November 21, 2013

BTAT Editorial: Over Reliance on Computers is a 21st Century Problem.

©2012 Boston to a T
A group of San Francisco subway riders were in for a frightening and wild ride last Wednesday morning when their train departed the station without its Operator. The Motorman of the outbound K-Ingleside Muni Metro train had momentarily stepped out of the vehicle at Castro Station to fix a door that would not close. When the door slid shut the train, which was in automatic mode, departed the station leaving the transit worker stranded on the platform. Passengers aboard the car scrambled to find a way to stop the vehicle; eventually using the emergency brake to stop the driverless train.

Muni trains, which operate manually above ground, switch to an Automated Train Control System (ATCS) when traveling through the Market Street Subway; a practice which has been in place since the late 1990s. When operating in automatic mode the Motorman has no control over the movement of the vehicle, but still cycles the doors at each station and makes necessary announcements.

Muni Transit Director John Haley reaffirmed his support of the automated system while attempting to squash concerns about passenger safety. Haley said “I think the point here is the train was under control by the automatic train control system at all times. The system worked the way it was designed.”

And that is where Director Haley is wrong.

While Muni’s ATCS was designed to remove human involvement from the running of trains underground, humans were never intended to be removed from the operation of trains underground.

As far as safety is concerned Muni Motormen serve an important purpose in the subway by acting as the eyes and ears of the blind and deaf SelTrac ATCS. Should the ATCS fail to brake properly or if an obstruction were to block the tracks, the Operator onboard is instructed to use the emergency brake to stop the vehicle and protect passengers.
Although Muni insists the ATCS is effective both with – and apparently without – a Motorman, the concerns over automatic train control are ones that shouldn’t be ignored.

When Muni first introduced the SelTrac ATCS in 1998 it was plagued with problems. These problems including trains that bypassed stations, trains that followed the wrong route, and trains that went into emergency for no reason at all.

Despite expensive software upgrades and years of tinkering, the ATCS is still one of the bay area transit authority’s biggest headaches.

A review of Muni’s on-time performance in 2010 found that metro trains failed to connect to the ATCS more than 200 times every month, each time grinding service in the Market Street Subway to a halt.

These service crippling computer glitches have generated a colloquialism in San Francisco over the past decade. They call it a “Muni Meltdown”.

While computer glitches that stop service may be an annoyance, other ATCS glitches around the world have caused injury and loss of life.

Two separate accidents in Beijing in 2011 injured a combined 450 people and killed 39 when newly implemented computerized train control systems failed to stop two trains from hitting stationary ones in front of them.

San Francisco’s other automated subway system, BART, has also had a series of incidents regarding their computerized controls; including a test train that ran off the rails and into a parking lot.

The most high profile accident regarding automatic train control was the 2009 DC Metro crash. The accident, which claimed 9 lives, was caused when the ATCS failed to recognize the train in front of it sending the striking train into a stopped train at full speed. A similar accident occurred on the Metro in 1996 resulting in the death of the train Operator.

As part of a safety agreement between ATU Local 689 and the WMATA the DC Metro has been run manually since the 2009 crash.

While proponents of computerized train control systems can point out accidents caused by Motormen on manually controlled subway and rail systems there is an enormous difference between the two.

An accident caused by a Motorman in manual control can be corrected through progressive discipline or retraining, and can be used as a teachable example to other Motormen to avoid a similar accident in the future.

An accident caused by a glitch in a thoughtless, heartless, and inanimate computer system cannot be predicted, cannot be corrected, and cannot be prevented.

Susan Moore, a passenger on the driverless train, perfectly summed up what it was like to be on that train. In an interview with San Francisco’s ABC-7 she described her and her fellow passengers’ concerns. “We didn’t know if a train was going to come up…” Moore said “For Muni to make light of it was really upsetting, because… You weren’t there”.

The blind faith that Director Haley and Muni have placed in their ATCS is emblematic of the over reliance our 21st century society has placed on technology.

This editorial was written and edited by Dan Lampariello & Scott Page





3 comments:

  1. I'm actually quite disappointed at how myopic this article is, considering the very same structural financing issues threaten to undermine operations under human control here.

    The 'accident' in SF could have been prevented if the driver had put his/her train out of automatic the moment s/he stepped out of the cab to deal with the door issue. THAT is the problem. The train would've merrily taken the passengers to the next station without colliding into any trains in front of it.

    In DC's WMATA, the accident was due to structural failures in track circuits failing to detect the train. The train stopped correctly in its fail state when it loses contact with central speed authority. The only failure was the original programmer's assumption that track circuits would not individually fail and continuously track trains, stopping all trains on the system upon loss of detection of a train.

    Beijing's causes haven't been fully explained, but a confluence of issues, including incorrect manual operation and arguably China's over-aggressive build-out have been to blame. The system was using a version of signalling based on ECTS, the European train signalling and control system that is nearing ISO acceptance.

    Japan has operated for nearly 50 years without incident using their train signalling and control system. The most recent high-speed crash in Spain happened BECAUSE of a lack of train control to properly calculate and apply a breaking curve for that section of track, overriding a driver who failed through whatever excuse he had to react to the speed restriction.

    You can't look at a bunch of incidents where trains operated on control systems and casually deride these operators as being over-reliant on life-saving computer control technologies. I'm incredibly disappointed that you didn't bother to take a step back and see that many of the failures are infrastructure-investment related.

    You're also confusing two different types of problems and control technologies. 'Automation' is not the same as 'control'. WMATA's and MUNIs trains can be set to automated, but there is no provision in the CTCS system on the Chinese high speed rail for automation.

    If you want to argue about automation, London's Docklands Light Railway uses SelTrac's CBTC, which is an automated system, to fully drive the trains without a human. Staff on those trains only take tickets, in place in case of the need for manual operation. All of Vancouver's SkyTrain operates flawlessly with SelTrac's CBTC. In my home town of New York, the CBTC installation on the L has been beleaguered by issues of tunnel infrastructure. Their upcoming install on the 7 train should be swift and problem-free since the East River tunnel has been extensively renovated since Hurricane Sandy and much of it is above ground.

    That's just a small selection of many large, nuanced systems that operate flawlessly because of proper investment or continued investment.

    We don't live in the dark ages of technology where we had to lay thousands of miles of copper to set up a proper signaling system. We also can't afford to shun these technologies. Editorial or not, these agencies will continue to expand their lines with CBTC or some other level of automation and/or train control to efficiently and safely move passengers through their urban metros. It's not fair to the public or anyone who reads this to be misled into thinking that this reliance on these vetted safety technologies is as simple as teen obsession with texting or Facebook.

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  2. This editorial is a disgusting piece of neo-Luddite nonsense. You should be ashamed, and should retract it.

    Unless you've invented a way for the human eye to see perfectly around corners and long distances, signalling systems will always be necessary for railroad trains. Inserting a human layer between the signalling and operations aspect of railroad safety is just asking for human error to intervene.

    You hinted at driver error causing crashes, but glibly dismiss it as a "training issue". It is not a training issue. It is a fundamental problem with human control. People make mistakes. There are numerous examples and that is one of the reasons why Congress mandated Positive Train Control.

    The automatically driven MUNI train was perfectly safe, because all those trains are automatically driven in the tunnel. The driver is a pacifier for neo-Luddites, and a sop to the Carmen's union. Republishing some alarmist nonsense from a woman who is completely clueless about how trains operate is below you.

    Incompetence in implementation of safety systems is something that can be corrected, and once fixed, is fixed forever. Training drivers to not lose focus, to not have health problems, to not accidentally miss a signal is a constant struggle against human nature.

    You are blaming a computerized system for a human error, do you not see the irony in that?

    The Red, Orange and Blue lines all use a form of automatic train protection (Blue being an older system of mechanical trips). They are absolutely dependent on the correct functioning of their computerized signal systems. There is no alternative. If you want to abandon computers, then you can forget about upgrades to capacity, and can instead expect immediate downgrades and slow orders.

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