
How 2 M.T.A. Decisions Pushed the Subway into Crisis - blondie9x
https://www.nytimes.com/interactive/2018/05/09/nyregion/subway-crisis-mta-decisions-signals-rules.html
======
rayiner
> After a 1995 collision of two trains on the Williamsburg Bridge killed a
> train operator and injured more than 50

Overreaction to safety incidents and inability to do cost-benefit analysis
cripple American transit systems. DC's Metro, for example, was designed for
trains to be driven automatically ("ATO"). In fact, they operated in automatic
mode for _decades_ , since the system was built in the 1970s. But in 2009,
after nine people were killed in a collision, the system was disabled, and
will remain disabled indefinitely.[1]

The result of disabling ATO is that what was previously a very smoothly
running system has become a disaster, with human operators lurching into
stations, then lurching some more to place the train correctly relative to the
platform. Almost a million riders inconvenienced every day for a decade, just
to avert recurrence of an incident that resulted in a handful of deaths in 30
years of operation.

[1] [https://ggwash.org/view/62992/metro-kicks-the-automatic-
trai...](https://ggwash.org/view/62992/metro-kicks-the-automatic-train-
operation-can-farther-down-the-road).

~~~
solutionyogi
I hate the driver who pens the L line going to Brooklyn from Manhattan. He
speeds way too much and then breaks way too hard. I have seen passenger fall
because of it time and again. If we can't get rid of the union workers, I
would rather have MTA pay these guys wages to sit at home and replace them
with computer-driven subway.

~~~
lobster_johnson
I've never been bothered by that (and as others point out, the L is automated,
anyway). What _I 'd_ like to know is why, when the L reaches the 8th Ave stop
in Manhattan, the operator waits 10 seconds after coming to a full stop before
opening the doors. The train has already stopped, so this seems unnecessary.

There's also this weird thing where, while the train is sitting there waiting
to return the opposite way back to Brooklyn, they close all the subway doors
except one in each carriage. It doesn't prevent people from getting on.

~~~
jrockway
They do this at every terminal. I have no idea why.

~~~
lobster_johnson
I found an answer here [1], via a Reddit thread [2] (where the answers are
apparently gone):

    
    
        I won't go into details, but if the conductor wants to exit
        the train and leave the doors open at the terminal, he needs 
        to walk to the next car at the last stop in order to open
        the doors, which is why there's a short delay before they
        open. If the doors open immediately at the last stop, then
        it means the train is either going to go to the yard, or the
        crew is going to manually key open one door per car (which
        is only done if the train is going to sit there for at least
        10 minutes, and helps the air comfort system).
    

[1] [http://www.ibtimes.com/mta-worker-goes-underground-share-
sub...](http://www.ibtimes.com/mta-worker-goes-underground-share-subway-
secrets-reddit-top-10-reveals-324984)

[2]
[https://www.reddit.com/r/IAmA/comments/kx5fa/iama_new_york_c...](https://www.reddit.com/r/IAmA/comments/kx5fa/iama_new_york_city_transit_subway_conductor_ama/)

~~~
jrockway
Very interesting. I definitely always hear the conductor moving between cars
at the last stop but I never connected that to being why the doors can't be
opened.

I think it's funny that the train's computer knows it's the last stop and
announces that fact to the passengers... but the conductor has to manually
override some sort of system before he or she can exit the train.

------
zaroth
I had to read a little bit to find the _real_ reason - combine faulty signals
which trigger over-speed warnings when they shouldn’t — with the following...

“Train operators face steep penalties after a number of instances of tripping
a signal, like losing vacation days or being forced into early retirement.”

That’s a recipe for exactly the problem they are seeing. Fix the signals. Fix
the policy. It will fix the problem.

But I also suspect this whole thing is much more intentional than we are being
led to believe — it’s actually intentional policies which have led to
_expected_ slowdowns in a jaded attempt to boost funding. The whole narrative
around overcrowding has collapsed. The narrative around underfunding is also
collapsing. But I’m not sure the other shoe (proof that this was a charade to
increase funding) has dropped quite yet.

~~~
dsfyu404ed
We live in a society where all the actors in the system need to virtue signal
about how much they care about safety, usefulness of the system be damned.
That's why the draconian speed limit policy in the first place.

The union wants the trains to go slow so they can say they're fighting for
policies that protect workers. The MTA wants signal enforced speed limits so
they can say they're preventing crashes.

If we could just have an adult discussion about the damage of marginally (if
at all) increased risk compared to the benefits of a more functional subway
system this wouldn't be as big of a problem.

This isn't even a resources issue, changing policy is close to free.

~~~
gamblor956
_The union wants the trains to go slow so they can say they 're fighting for
policies that protect workers. _

Have you ever performed maintenance literally inches from a train going 40mph?
The union has valid safety concerns for wanting trains to slow down in the
vicinity of workers, and this particular safety measure only applies to late-
night routes when they are performing maintenance on closed lines that share
tracks with operating lines.

The problem is that the MTA introduced a number of other "safety" measures
that did nothing to affect the safety of workers or employees, such as
increasing the distance between cars or introducing speed-limiting signals,
and these other measures apply 24-7.

~~~
dsfyu404ed
Trains don't need humans to steer them and the humans there are being paid to
(presumably) operate them safely.

Cops and tow truck drivers have more exposure to worse traffic going faster
for less pay and nobody is in a hurry to bring back the national speed limit.

I'd take working on tracks over changing someone's tire on the side of the
highway.

~~~
bobthepanda
Trains also have really long braking distances. If you can see a track worker
in the way, it's already too late. Hence the declaration of these work zones.

In my areas, they usually close a lane next to the accident in addition to the
lane where the accident occurred. This is basically the exact same thing.

~~~
slededit
They close an entire highway lane for the towtruck moving a stalled car off
the shoulder? Not all towtruck work is related to accidents, in fact most of
it isn't.

~~~
dmckeon
Many US states require drivers to move over, leaving an empty lane next to
emergency workers. Specific state laws vary for law enforcement, fire and
emergency medical, highway workers, tow truck operators, and disabled
vehicles, but while all states appear to at least nominally require moving
over for law enforcement. California does not seem to notify drivers on the
road much, but other western states do notify/advertise much more, and Indiana
and Ohio are fairly vehement about it.

[https://en.m.wikipedia.org/wiki/Move_over_law#In_the_United_...](https://en.m.wikipedia.org/wiki/Move_over_law#In_the_United_States)

------
kevin_b_er
The negative feedback loop on faulty signals should be a read for anyone doing
engineering, including software engineering.

If the workers go the proper speed, the faulty signal will trip an emergency
break. This actually threatens their jobs because they'll be blamed for
tripping the e-brake as if the signals worked perfectly.

1\. The management trusts the automation too much without proper checks or
tests proving the automation is accurate. 2\. These workers are still blamed,
even after signals are known to be bad. 3\. People, even in here, blame the
workers (and the union) for the fault of the system's quality being garbage.
4\. Workers try to preserve their jobs by just working around the problem and
reducing productivity all-around.

~~~
jrockway
I'm not sure. The incentives could go either way. If the incentive is "on time
performance is a must and the signal system is not going to check your speed",
then people would drive the trains over the recommended speed to make the
schedule, and thus derail the train around curves or not keep the speed low
enough for the block system to provide adequate train protection.

As it stands now, the incentive is to not get "tripped", so people drive the
trains well below the speed at which the signalling system will trip the
train... doing anything else runs the risk of getting yelled at or worse, and
nobody wants that, so they play it safe.

A computer can be programmed to take into account both concerns and drive the
train at the exact speed to satisfy all the constraints of the signalling
system. If a computer gets tripped for travelling through a block too quickly,
a meeting is had and a fix is checked in. The software doesn't care if you're
mad at it. You just fix it and move on. Humans are more fragile, and if you
don't align the incentives correctly you will not get the right result.

------
kaycebasques
When I first learned about computer networking, I remember being blown away
when I learned that network congestion dynamics also explained how freeway
traffic worked. It’s cool to see the same idea in this article!

Specifically, I thought it was amazing how it explained why if someone stops
abruptly on a crowded highway, every subsequent driver will have to experience
that pause, even hours later, so long as the highway maintains the same level
of congestion.

You network folk will undoubtedly explain it better than me, but I think
that's the correct gist of the idea?

~~~
paulmd
I've always had this odd feeling that traffic is actually a Bernoulli flow,
where instead of "pressure" you have congestion.

eg if you have two lanes merging and the system is at capacity, then the
"pressure" across the streamline increases and traffic slows down as a result.
And when you have very little pressure (or diverging arterial roads) traffic
tends to speed up.

Of course there is a secondary problem of "phantom" traffic jams where the
system is not really slowing down due to traffic merging or anything, you just
have spots where traffic is not flowing at all for no real reason (the optimal
solution being that everyone puts their foot on the gas and accelerates
together). I suppose the physical analogue might be cavitation or non-
laminar/turbulent flow?

I can't find any academic references on this but it's always made intuitive
sense to me.

~~~
lainga
This is exactly why traffic regimes are sometimes described as "laminar" or
"turbulent".

[https://en.wikipedia.org/wiki/Fundamental_diagram_of_traffic...](https://en.wikipedia.org/wiki/Fundamental_diagram_of_traffic_flow)

------
nisa
Strange how the article blames the workers and unions while also admitting
it's not their fault.

\- cheap and worse brakes appear to be the initial error beeing made

\- lack of control over their signals and blaming the workers for it is not
excusable. Also there must be some kind of cheap and reliable assistant that
can calculate the maximum velocity and help the driver.

\- badly organized maintenance is also not the workers fault.

~~~
aeorgnoieang
> Tony Utano, the president of the Transport Workers Union Local 100, said he
> would fight any rule change that could put workers at risk.

Given that any change "could put workers at risk", it seems pretty clear that
the union's are _likely_ to be _somewhat_ to blame.

Surely the _train operators_ are not to blame for bad signals but why then is
no one else at the MTA to blame? Are the workers that installed the signals
not union members too? Are _none_ of the MTA managers union members?

~~~
thirtyseven
Managers are generally not allowed to be union members since they have an
adversarial relationship with the workers.

~~~
dragonwriter
> Managers are generally not allowed to be union members since they have an
> adversarial relationship with the workers.

Managers are generally not allowed to unionized because they aren't covered by
the federal law which protects that right; where they are unionized (which
happens in some public sector areas) it's usually not in the _same_ unions as
their employees, for the reason you discuss.

------
jrochkind1
Sounds like there could be large benefit from A) removing the punishment for
tripping the signal, that causes drivers to go extra extra slow (well under
safe and officially regulated speed) cause they know there are faulty
unpredictable signals which they'll still get punished for tripping; and B)
fixing faulty signals (which they probably don't even know about when all the
drivers are slowing down so much in case of faulty signal that they don't even
know which ones are faulty).

Contrary to the article saying "And there’s no easy fix", it seems like this
would be a fairly easy fix?

~~~
rohansingh
From a moral standpoint, it's definitely wrong to punish drivers for signal
issues, and we should stop doing that.

However, if drivers all started going at the normal speed and regularly
tripping broken signals, it would absolutely destroy the system. When a
train's emergency brake is tripped, it takes tens of minutes to reset it and
get the train going again. If that was happening at every faulty signal on a
daily basis, the system would grind to a halt.

Really the only fix is dealing with the signals. But that's extremely
difficult because they haven't been regularly maintained and are very old.
Most of them use mechanical timing systems and other insane things that nobody
has built parts for. There's no particular reason to believe that "changing
them back" would go any better than the botched rollout of the initial change.

~~~
bluGill
Sometimes if something is hard you should do it more often so you get good at
it.

That is workers should be rewarded if they trip a system and after
investigation it is proven the system was wrong. That worked just found a real
bug and it needs to be fixed.

------
makomk
"The London Underground, a system of similar size and age, has had no track
worker fatalities since 1998."

As far as I can tell, the London Underground only allows work on sub-surface
and deep tracks when the line is completely shut down. Like, not just slowing
down trains on the tracks either side of the work, but not running trains on
any of the tracks full stop.

~~~
jkaptur
Also, as I understand it, the line shuts down each night.

------
jessaustin
It seems stupid to use these unreliable "signals" at all, but even if they
have to use them for "safety" they don't have to use them for operator
evaluation. It would be real easy for every operator to carry a device that
could prove e.g. she drove an appropriate speed even though her train tripped
a poorly-maintained signal. I'm not foolish enough to imagine this would lead
to the signals getting fixed, and from a political perspective it might be
important to stipulate that it wouldn't, but that seems secondary to the
horrible schedule problems that tentative driving has caused.

~~~
gamblor956
What sort of magical device would accomplish this feat? It couldn't be GPS-
based, as GPS signals wouldn't penetrate to the subway level. It couldn't be
momentum-based, because that's not sufficiently accurate. It couldn't be
connected to the train's computers because that would require major upgrades
to every train in the system, which would take decades.

~~~
jessaustin
I don't have an amazon link for you, but it doesn't seem that magical to me?
Submarines have had inertial nav for decades. This is a simpler problem,
because travel is restricted to rails and drift can be corrected as often as
necessary. Every airbag in every automobile is equipped with a very accurate
fairly inexpensive MEMS acceleration sensor, which would the only specialized
component required for such a system. Hobbyist components like the ADXL345 are
also cheap. It wouldn't surprise me if such a system already exists for e.g.
tracking underground mining equipment, but if not it wouldn't be an impossible
task for an organization with the budget of MTA. It's not as though the system
would need to be incredibly precise; it's replacing one that at its best can
only measure average speed over some huge distance.

~~~
gamblor956
Submarines also need to surface periodically to verify their navigational
position as dead reckoning is frequently off by a margin.

Airbags are equipped with acceleration sensors that have a very simple test:
is the acceleration force greater than X? If so, deploy!

The point of the system is to have a system that is accurate enough to replace
the current system, which neither of your solutions achieves.

~~~
jessaustin
Yeah that's what's meant by "drift". Submarines correct every few thousand
nautical miles. The hypothetical device could do so at every station. The
current system is not accurate at all, and even if it were is quite imprecise
by design.

But you've convinced me. A much better solution would just be a camera pointed
at the speedometer.

------
jdlyga
This is the best article I've ever read on the subways. So many people blame
so many factors: people holding doors, overcrowding, badly made signals, etc.
But this explains it very well with clear visuals.

------
dajohnson89
Awesome visualizations.

~~~
gorbachev
Absolutely! One of the best use of visualizations to support a story I've seen
ever. New York Times in general does a great job with visualizations.

------
Dowwie
This is a great use of visualizations. Bostock made his mark while at the
NYTimes.

------
jakelarkin
how hard is it to put a location based speed governor on the train instead of
using antiquated mechanical signals to enforce max speeds? or is that just too
much common sense for the MTA?

~~~
gamblor956
It would be extremely difficult. How would the train know where it is? GPS is
unusable at that depth. You'd need location beacons...but at that point you're
better off just using signals, like they already are, rather than upgrading
every train and dealing with the ongoing maintenance of making sure that each
train's location-based speed governor is properly up-to-date with all proper
slow-down locations.

~~~
mortehu
Could you please explain why positioning would be hard? Since trains only move
on the edges of a fixed graph, you'd think positioning would be super easy
compared to almost all other indoor positioning applications.

~~~
gamblor956
Your indoor positioning applications would require the installation of
numerous positioning beacons--or in other words, significantly more hardware
than the many thousands of speed signals they have already installed and are
unable to maintain.

------
gniv
Didn’t MTA say they are increasing the speed limits after the Village Voice
article was published?

------
parliament32
Meta but the interactive visuals are great! They're an excellent supplement to
the text.

------
dopamean
Losing your job over a faulty signal sounds like some serious bullshit. I hope
they sued.

------
mwexler
While I love interactive docs as much as the next person, I wondered if all
these demos were really necessary to get the point across in this particular
case. The text did a pretty admirable job, along with a few charts. Did the
more graphical pieces help, or were they more of an "ooh, pretty" feature?

~~~
ams6110
Close reading of text for information is a dying skill.

If it can't be stated in 120 characters or presented as an animation, you've
lost a big part of your audience.

------
ggm
root cause? undercapitalized.

