Wednesday, April 8, 2009


This item made us laugh and cry.

OK, so Metro has automatic train controls, which ostensibly would help the train stop more precisely so they would neither undershoot nor overshoot a station. Sounds good, but Metro opts instead to "put the operators in charge of the stops for much of the day." Well, OK, we guess. Good to have a human in charge.

But--and here's the kicker--the drivers can't seem to remember if they're driving 4, 6, or 8-car trains, so they over and undershoot stations all the time!

You want them driving your heavy machinery?!

Dr. Gridlock's conclusion: "I think the goal should be to have precise automatic train controls that can stop all trains at all times in the right place."


He also says "I vote for whatever method ensures that the train doors don't open in the tunnels" because "some passengers at the rear of the train are in danger of stepping out onto the track bed."

If you're going to step off a train that's still in the tunnel, you're more of a dim bulb than the driver who can't remember what size train they're driving.

Can you believe this is even a serious discussion about the nation's second most used mass transit system?

How come in Japan, for example, the trains stop so precisely that the location of the doors is marked ON THE PLATFORMS? The photo is from the Fukuoka subway.

Of interest:
An appreciation of Metro's architecture

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Anonymous said...

simply amazing. what a rickety system

Unknown said...

I could be wrong on this, but I am fairly certain that ATC is disabled due to a problem with the system properly recognizing and dealing with eight-car trains (if there are any operating at the time).

I think instead of switching ATC on and off throughout the day, WAMATA made the decision to leave if off all the time until the problem can be completely resolved

Unsuck DC Metro said...

Obviously something it not right with the ATC, or they'd use it. Then again, it is WMATA. Maybe they could give the riders little cards with the number of cars written on it that they could put on the dashboard as a reminder.

Mainland said...

ATC is disabled for 8 car trains since the stopping precision in automatic mode isn't fine enough to stop the train on the platform the vast majority of the time. So, all 8 car trains are operated manually. However, many 6 car trains (even last night on the red line) still run on automatic.

What WMATA made the decision to turn off all the time was the automatic door opening system. (Supposedly due to technical malfunctions...not user errors....)

The precision stop system was supposed to be upgraded by the end of 2008 (but my guess is it's not), a fix for the door issue was said to be a bit further away as I recall.

Tim said...

In fairness to Metro (I am a big critic), while the jerky stops are tons of fun, I can usually pinpoint a specific door I want on each train within a few feet. In the morning I will get on near the end to avoid the Chinatown cluster eff. And again so as to get off right at the Crystal City escalator and avoid the pileup. Then at night I will time it and usually will be one of the first at Wheaton so I avoid the bottleneck.

Anonymous said...

I've ridden subways all over the world -- NYC (my hometown), SF Bart system, London underground, Paris Metro, Chicago El, etc etc, and while they all have their considerable flaws, DC Metro train operators are the worst by far. Why do you even NEED an automatic stop system? Are the operators too incompetent or too dumb to stop the train at the right spot? (Don't answer that.) Seriously, I'd like one train operator -- just ONE -- to explain why this is so hard here but not every place else. And "New York subways are dirty" or "London's Underground is musty" or other such comparisons are not an answer. We know what the problems are there. Does DC Metro even know it has a problem here?

Matt' said...

Mainland is correct.

The ATO system has never been precise enough to dock 8-car trains. MARTA in Atlanta has the same problem, except that they almost never operate 8-car trains. In the 1970s, computers just weren't perfect enough to deal with the variation. One solution would have been to make the platforms slightly longer, but there's expense there.

So WMATA has always operated 8-car trains using manual operation. Until recently this was not a problem because 8-car trains didn't happen too frequently. However, with more and more 8-car trains in the system, WMATA decided to upgrade the system to allow 8-car trains to be operated by the ATO system.

But there was a problem. The new system caused the automatic door opening feature to open the doors on the wrong side of the train. So, WMATA turned that feature off. Doors now take longer to open at center-platform stations because the operator has to cross the cab.

So, while the system is being worked on, 8-car trains still operate on manual. Other length trains can also operate on manual if the operator chooses to do so. This is what creates the circumstances for an overshoot/undershoot scenario. Operators who are used to stopping in the same place on the platform, might accidentally stop there even when their train is longer. When that happens, not all the doors will have platformed.

I agree that operators should be expected to remember where to stop. They should remember how long the train they're driving is. But mistakes happen. Imagine, if you will, that you're driving home over a route you've taken for years. Along the way, the DOT has converted a stop sign into a red light. While you drive, you automatically come to a stop, even though the light is green. It can happen to anyone. It's an automatic response. There's no excuse for it, but WMATA can't take the risk that it will happen - because of liability.

It was never like it was commonplace. It happened a few times, and for a system that operates hundreds of trains a day, it was a very small percentage. But WMATA considered any risk for error to large a risk to take.

As for passengers getting off before the train has platformed, the issue was not someone stepping off into a dark tunnel whilst thinking they were at the station. The problem was people who lean against the doors or who might get pushed out an open door in a crowded train. When there's a platform to catch you, this isn't a problem, but when there's just a dark tunnel out there, it's a bit more serious.

Anonymous said...

People shouldn't be leaning on the doors! Metro says that again and and again and again.

Unsuck DC Metro said...


You seem to know a lot. Thanks for the interesting post.

How long has Metro been working on the issue with the 8-car train doors?

Also, as another reader asked, why is an ATO system needed anyway? Can't the drivers be trained to stop consistently?

Anonymous said...

BART has 8+ car trains and they are sophisticated enough to be able to mark the platform where the doors will be.

Mainland said...

BART uses a different ATO system than WMATA.

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