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New York Computerizes its Subway System
Iphtashu Fitz writes "New York City's Metropolitan Transit Authority launched it's first fully computer controlled subway line this month. The `L' Line of the MTA that connects the southern part of Manhattan with Brooklyn was picked for this pilot program because of its relatively short length and the fact that it doesn't share tracks with any other lines. Trains on this line no longer have conductors on board, and only a single driver in the front to monitor all the systems.
What's the big deal, you may ask? After all, cities like San Francisco and Paris already have computerized subway lines. Well, having recently celebrated its 100th anniversary the MTA is one of the oldest subway systems in the United States, and one of the largest in the world. If all goes well, the MTA will continue to expand automated service to the rest of the subway system over the next 20 years. But just how safe and secure will these new automated lines be? The radio links that provide data communication between the trains and the control center are encrypted, but how long until a hacker manages to crack it?"
In New York, train dwell times--time spent in stations--can be frustratingly long, especially during rush hours. Besides people pushing and shoving to get on the train, you've also got the jokers who hold the doors for their friends who're still running down the stairs.
Without a conductor, who's going to yell at everyone to stop holding the doors? How does this work in other automated systems, like Paris's Météor?
I was in Jr High when BART was being built. Our school's computer classes were given access to the SINGER computer that was setup to run BART.
We as students had great funny trying out the different options avaiable at the time. We tried to get into train control programs to see what we could do.
I think the guys at BART were using us to test security on system. One week we would be able to run train control and "race" trains (actually just the train objects, the tracks were not even layed yet!) and the following week we weren't.
MTA in should let students help in debugging the logic... because we as students did not know what was or was to work... we just played.
You might be able to ID each train by its engine's impedance to current flow on a segment of track, though that might be affected by the load on the electric motor.
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seems that recently a portion of the subway burnt down and when the guys went down to repair it they found that the hardware driving the system dated back to the 1930's. After more digging they found that the original systems laid in the early 1900's till 1920 were still operating and actually in daily use in many other parts of the subway. point is that thing is working well that they dont want to touch the thing. the other fact is that there is no way they are going to get the thing changed without majorly affecting the daily workings of the system.
Trains on this line no longer have conductors on board
I dunno about the rest of you, but I want a conductor on the train. Things like having a human look outside the train to make sure nobody is about to get on when the doors close, having someone on the train in case of an emergancy, having someone on the train that is a detterent to crime (just imagine, would a would-be rapist be more or less likely to rape a woman if a conductor was walking up and down the cars).
And part of me feels bad for the guy losing the job, the conductor.
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To have a truly integrated system, the city would have to continue buying all its equipment from Siemens AG, effectively giving it a monopoly.
This also raises a red flag. One company that will in effect control the whole parts system? How can we know we won't get hosed with the price?
Even if they do autimate, lets keep the conductor. Someone who knows how the train runs. Someone who can over-ride the computers if needed. Every vessel needs her captin.
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Take a look at the way the power grid works (or is intended to work). The big North America power shutdown two summers ago was that a power plant in north eastern United States sent bad data to the grid, which triggered a shutdown. It's better to be safe than sorry.
While I agree it could have probably tried to isolate the problem more rather than a full shutdown, I'm sure it was designed this way for good reason with more serious problems in mind.
If signaling gets interrupted, really all trains should assume the worst- that there is another train or object right in front of them and stop. Now this means that anyone with a jammer above ground of some sort could shut down the subway line... but again the lesser of two evils.
They should really consider instead some sort of 'data' rail or something. I wonder if data over the power rail works with such high voltage?
How are they going to take into account kids on the tracks and stuff. I realize this is underground and a subway, but there have been cases where kids explore the tunnels late in the evenings when the trains are sparse. You can get to most of them through various access points taht are often pretty accessable to those with some intuition and a willingness to climb.
-M
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What the MTA really needs to do is publish realtime subway position info. On billboards in the stations, on their website, on automated phone lines, as a pager/sms subscription/request service. Millions of us use it daily, wasting millions of hours of America's most productive workforce as we wait for trains, miss express connections, clog stations. The uncertainty keeps many people using cars and taxis, which make the roads even worse. Automating subways will save a few million a year in conductor costs, out of an $8B budget, which will be lost every day in the productivity of our workers. But I guess MTA contractors don't get a cut of the productivity gains from sensible priorities. Thanks Mayor Bloomberg, and Governor Pataki (who controls the MTA), and Sir Giuliani, who blew the only real chance of taking the subway back from the state for the people who it actually serves.
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I am seeing a trend that cities are doing. They are installing tons of camera's, in the 1000's range. I think Chicago now has over 3000 camera's the police can use. I got a ticket in the mail a few weeks ago, it was a camera attached to a radar gun. They are removing people, and adding technology. Technology can't think, it can just do what it's programmed to do. And you are right, if terrorists knock out these systems, or hack them, then what? They will be watching us, controling our trains, and controling our electricity. Maybe law enforecement is making a honey pot, I dunno.
But I doubt terrorists would hack the system to hijack a train. They would just program them to run into each other at high speed. Terrorists don't care about stopping one train, they want to make people afraid to use the trains at all.
There is some psychological comfort of having a conductor. A conductor would force terrorists to come on the train, because if he saw an oncomming train on the same track, he could stop his train. It would take a boat load of osama's to hijack the train I would be on. Then the train passengers could get revenge for 9/11. But it would take one hacker to reprogram the train route and what tracks it uses.
Rosco: "If brains were gunpowder, Enos couldn't blow his nose."
I wonder if instead of using radio, if they could devise a way to send the signals down the track? That way the hacker would have to risk their life to try to take over the train.
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I'm not sure how useful this fancy automated system is. The current automatic block system with mechanical stops is VERY reliable, having had 100 years to be refined. It also has been shown to be fail-safe, and has capacity for 30 trains per hour (and up to 40 in more refined variants). The fail-safe mechanisms on railroad signal logic are amazing. Relays have weights on them rather than springs, because springs are more likely to fail. Everything is very very carefully designed to not fail, or if it does fail, to do so in the way that is safest.
The new system, however, is based on computers. The way it detects trains is by ping latency. So a train basically has to tell the system where it is, and the system tells the train how far it can go. As for hackability, I think the system is based either on plain 802.11b or some derivative of it. It's really plenty hackable.
Does it provide anything in terms of safety? Not really. The only reason that accidents happened was because the signal system was badly designed or the train's brakes failed to work correctly. Also, the BART signal system was known for its spectacular failures in the early years. However, at roughly the same time, the all-automated PATCO system opened which used primarily coded track circuits rather than a computerized packet network, and has not had any problems since then. Same goes for many other systems, such as Boston, Washington, etc.
Finally, there's definitely quite a revolving door between the MTA and the various consultancies pushing these CBTC systems.
I would like to point out that in Moscow subway system, a fully computerised line (grey line) was introduced in early 80's. The rest of the subway stayed with proper drivers. In early 90's there were two crashes (within several months of each other) on the computerised line. The reason was that due to technical problems one train stopped, and the train behind it slammed into it. The curious thing is that the traffic lights in the tunnels correctly lighted red (since they are redundant, in case of such emergency to display red just behind the train), but the computerised train (without a driver) carried on. If the driver was there to stop it, it wouldn't have happenned. I beleive that grey line is still the only one that is computerised and they have drivers on every other line. For more information on Moscow Metro see photos here: Metro map Cheers, Alex.
This morning I had one of the most peaceful commutes in quite a while. I attribute it fully to the conductor, urging us at every stop to "Step aside, let others off before you get on. If you can't fit on the train there is another train right behind this one."
The new system will not do this.
Even if it works flawlessly, many will still resent it for a long time. The installation phase has been shutting down sections of the line for 3 years every weekend, often for months at a time. It was pretty annoying to have to wait in a station for 35 minutes because only one train is running, only to see an empty car go by you on the" closed" track, carrying a few engineers with 15" powerbooks and some other random equipment.
People have tried to hack the metrocard system for years. The closest they came was a decidedly non-l33t solution involving demagnetising part of the strip relating to card expiration date. It gave access for a week, only because they MTA had the system set for "be generous". Some NYers, led by the local tabloid "The Daily News" tend to be moderate to extremely luddite when it comes to technology, and the metrocard was not welcomed with open arms. When it was first released the MTA went to great lengths to ensure that no one felt the metro card system was "ripping them off". So rather than properly rejecting expired cards (that may have had money on them, you see), they let them through. Some smartass realised that by erasing the part of the strip that contained the expiration date, the reader would automatically decide the card was expired. Since the system was set to ignore that on initial release, they got through. Once the exploit got out, they stopped it, iirc within 3 days of the first occurance (the system tracks this too, you see).
Things have changed since then, and in light of a recent subway fire that caused great inconvenience, NYers have gone the other way, wishing that the entire system was computerized. Yea, even the Daily News quite vociferously raised the cry for greater computerization in the MTA switching network.
The MTA is underfunded but not stupid or poorly run. The system is well designed and the underlying databases are also redundant and protected. The hardest part of the job for them is getting funding approved for their various efforts, they usually do a good job of executing once they get it. They've worked quite hard on this new system, it'll be a step forward in spite of the pundits.
With the complexity of the subway system in NYC, I don't think that it would be a good idea to computerize the subway system. Aside from the human aspect (conductors losing their jobs), there's the question of practicality. I take the subway to and from work every day and most of the time there are so many people jam packed in the train that you end up pressed against other people in most intimate configurations. There are probably anywhere from 1000 to 2000 people riding on each train during rush hour. Also, people act irrationally: some rush into the train as the doors are closing; some hang out very close to the edge of the platform; people try to leave as others are coming in, and so forth. All in all, it's pure chaos. On top of it, there's constant changes, repairs, modifications in service, floods. I'm sorry, I just don't see a computer being able to manage all this chaos. Given how progressive the city is in other aspects, the subway system is fairly antiquated but given its enormity and complexity, that may be the only practical way to operate it?
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This also raises a red flag. One company that will in effect control the whole parts system? How can we know we won't get hosed with the price?
You bring up a very good point. In some cases, it is abundently clear that technology has made the price of many goods dirt cheap. Examples include online stores (little overhead), web-based customer service (FAQs, forums, etc), and credit cards (all electronic). But in all of these cases, there has been lots of competition to drive the price down (usually to the point of disallowing ANY profit to be made from said technology). When there is so much competition, the revenue from automated technology often goes away because competitors will lower their prices to attract customers. Many business will start to just give away their computerized services for free.
But back to my point... If the only place NYC can obtain new parts and service from is Siemens AG, you can bet that the state is going to pay a premium for ANYTHING because they are locked in. The competition to force lower prices is eliminated, and it basically becomes another government beurocracy that just drains money from an otherwise good system. They need open standards for the new subway, so they change suppliers without a problem.
*Dealership mechanics will chagre $75 for computer-chiped keys, and also charge a fortune to diagnose the car's problem. A regular mechanic can tell you "its this, this, or this," but because they don't have the software and access to the car's computer, they can't tell you the exact problem the car is reporting. They usually want $50-100 just to plug your car into the computer to tell you the problem.
I am always glad about computerization, but it surprises me that you can't ensure uninterrupted traffic on a dedicated subway line.
In Russia subway trains are controlled by humans, but they still manage to ensure safe and reliable operation. The trains go with the interval as small as 90 seconds and still they manage to avoid congestion. Of course, the subways here are not 100-years old - more like 50-years old, but still.
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This is an incredibly detailed simulator, going all the way down to the relay level. You can work the control panels, look at the relay schematics, and see the signals from the train operator's perspective in OpenGL.
The system simulated, developed by General Railway Signal in the 1940s, is the first "intelligent user interface" ever developed. There were many earlier signal systems, and by 1914 or so they were routinely interlocked against operator errors for safety. But this one, NX, for "entry-exit" signalling, was the first one that offered intelligent assistance to the signal operator.
The train dispatcher selects a train entering a junction full of switches, signals, and trains. The NX system will then light up all the currently valid "exits", places the train can exit the junction, checking for conflicts with other trains and timing constraints. When the operator selects an "exit", with one button push, the NX system does everything else. It sets the track switches, verifies that they're in position and locked, turns the appropriate signals green, lowers the appropriate train stops (alongside the track are mechanical devices that, if raised, will be hit by an air brake valve on any passing subway car, bringing the train to a stop), and tracks the train as it moves through the junction. As the train clears each signal, switch or crossover, that resource is released so another train can use it.
The train stops come back up behind each train (and the signalling system verifies that they do so), so that separation between trains is maintained. Even speed control is enforced. There are timers all through the system, so that when a train passes one signal, there's a minimum time before it can pass the next one. An overspeeding train will be tripped and stopped.
It's all done with relays. Big relays, with silver contacts to prevent corrosion. It's fail-safe in a formal sense - no relay coil failure, power failure, or broken wire will result in an unsafe condition. Everything is designed to "fail to red". The designers trusted gravity and solid metal, and not much else.
Situations programmer types never think of are handled. For example, a train stop might become jammed due to ice. That's not only detected, it's handled properly. If a train stop protecting a switch won't go to the up (stop) position, the signalling system won't let the switch move. (And the gear is rugged enough that when someone goes out with a blowtorch to unfreeze the thing, it will be unharmed.)
This is a very safe technology. But it requires a huge, highly trained maintenance force.
There is a great book about the history of the NYC subway called "722 Miles", by Clifton Hood. (That being the length of install track - which if laid out in a straight line would take you all the way to Chicago!)
The book, which is available at Amazon, covers the types of mass transit systems that existed in NYC before the advent of the subway, and also covers the politics of getting big changes made, etc.
Another truly fascinating aspect of the book is where the author talks about how much of an impact the subway had on the development of the city.
A great read.
Anyway, in case anyone's interested.
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Copenhagen's is pretty cool as well. They have quite a new system, and it's nice and fairly efficient. I take it a couple times a month to go shopping or to meet friends, and sitting at the front is great, especially on the above-ground tracks.
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I like my DC metro smarttrip. This is a new plastic card with a radio transmitter (RFID). You just touch it to the SmartTrip cricle and you get through. You can load it via credit card and get a refund if it is lost. I keep it in my wallet, and just slap my whole wallet on the white circle. When I go through a handicapped gate with the circle on the side (as opposed to the top), I can keep my wallet in my pocket, and just knock it with my hip. I don't even break stride.
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