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by rob74 2178 days ago
> One peculiarity of human perception is that large objects in motion appear to be moving more slowly than they really are

Rule #1: if you are at a railway crossing and you see a large object in motion coming down the track, then stop and let that large object pass before you try to cross the tracks!

3 comments

Maybe this applies more to countries with faster trains? They only go ~30mph here and I never had any problem crossing tracks on foot with trains in the far distance, and the rest of my family did it too. These tracks also had a lot of curves though.
No, it’s really important advice.

The big issue with trains is that it has an inertia that our brain is not trained to.

As signalling engineers, we get to compute safe braking distances a lot and they are /big/, even at relatively low speed. This means that trains in curves -> do not have line of sight all the way to the next possible stop point <- so the driver may never have the chance to stop if you fall while crossing the track.

So don’t do it. Even at 30mph in curves, you are in danger.

I would always assume that if a train driver sees something on the track ahead, she is going to start braking. And I know that even if I believe I am going to be out of the way in time so they won’t have to stop (or hit me), merely causing a train to brake is going to cause inconvenience and delay and waste energy. So I’m not going to step in front of a train, ever.
Given that it's clear that this is not how people behave in practice, maybe we should take different steps to prevent the problem? Rather than blaming the user for the system's poor UX?

"Human error" isn't a very useful "root cause" for any incident. Humans make errors.

If there's a level crossing without an automatic barrier, that's certainly poor UX.

But if there's a working automatic barrier, and the user bypasses it? Tough to see how you could UX your way around that.

If people are reminded using novel imagery it can help a lot. A few years ago Melbourne introduced a campaign on its tram network that had a rhinoceros riding a skateboard to remind pedestrians/drivers not to cross/turn in front of a tram. It got people’s attention about the danger through a humorous analogy.

https://www.fizzicseducation.com.au/articles/science-in-publ...

https://www.youtube.com/watch?v=wdeqwNzMhJQ

> Given that it's clear that this is not how people behave in practice

Is that clear? Most people don't get hit by trains, so I don't think that's clear. I'd say most people are cautious around trains while a minority aren't, and a minority of those who aren't will get hit by trains.

That's a dangerous way of thinking, and is in contradiction of the article. It implies that people get hit by trains because they are stupid, and it'll never happen to me because I'm not stupid. I would imagine that most of the people who do get hit by trains don't think they are stupid.

There's a physiological reason why people have a tendency to underestimate risk in certain situations, or miss obvious pending collisions. The usual comment from someone who has had such a collision is "They just came out of nowhere". See also https://news.ycombinator.com/item?id=23024275

Airplane pilots (particularly military fast jet), and ship captains are taught specific techniques to deliberately and systematically overcome these physiological limitations. Some of the techniques are taught in some driving schools (for example https://news.ycombinator.com/item?id=18157090 ) and to be frank I think driving education should go all-out on it.

The article argues that it's difficult to judge the speed of a moving train, and I don't doubt that's true. However if you're attempting to judge the speed of a train at all while at a train crossing, you're already doing it wrong. The cautious approach is to stop and wait for the train no matter how fast you think it's moving. This is what I do every time. This is what drivers ed programs teach. It's what common sense dictates. It's what most people do, and is the reason most people don't get hit by trains (3000 collisions per year is not very many at all when you consider how many times people cross train tracks each day.)

Might I still be hit by a train I never saw at all? Sure. Somebody I knew in highschool was hit by a train on a track he believed was abandoned and consequently, never looked down (he lived after being pushed 100m down the track). It's possible that might happen to me, at least if I ever forget that it happened to him. But what won't happen is getting hit by a train I see and judge to be moving slowly or not at all, because I stop for any train I see no matter how much time I think I might have to cross the track.

> Airplane pilots (particularly military fast jet), and ship captains are taught specific techniques to deliberately and systematically overcome these physiological limitations.

The "specific technique to overcome this physiological limitation" is: Don't race trains. Don't race trains even when you feel certain you can easily beat the train. Racing trains is stupid.

> This is what I do every time

Nobody cares what you do all the time, though. In order to reduce accidents overall, we care about what the average person does. And if the average person does something else, then common sense isn't really the right term.

And even average person isn't the right bar. To really cut down on accidents, we need to see what the person who's behaviour is a couple of standard deviations less safe does in various scenarios.

> And if the average person does something else, then common sense isn't really the right term. And even average person isn't the right bar.

It's quite evidently you don't think the average person is the right bar, because the average person doesn't race trains. 3000 a year is next to nothing compared to other common hazards.

Maybe we should eliminate all intersections, since although the average person obeys signal lights and signs, the occasional idiot chooses to run red lights instead. We should eliminate crosswalks too; the average person looks both ways before stepping into the street, but occasionally people don't (this happens FAR more often than train/car collisions.) Let's ban bicycles too; the average cyclist wears a helmet but some choose not to and get their heads split open. Let's also ban self-service gas stations; the average person can pump their own gas without burning the station down but sometimes some people fuck up and cause huge fires. Doesn't that mean we should all follow the lead of Oregon and New Jersey and ban this activity? 'Nobody' cares that you can pump your own gas safely, please be considerate of the rare idiot who can't.

I love how this article tries to make this sound like a complex affair. Only the most ridiculously stupid person would be in a situation where they are continuously trying to judge the position of the train relative to their own position as they attempt to beat a crossing. The only situation where you should ever be remotely in danger is if all of your braking and steering catastrophically fail at that exact moment and there is nothing to stop you from rolling directly into the train.

I also find it amusing that all of the stories regarding train-car interactions seem to occur at crossings with modern signaling devices, rather than "at your own discretion" crossings in the middle of nowhere. This leads me to suspect that the typical human has been conditioned to treat any signalized intersection transition as a "beat the yellow" event, but in the case of a rail crossing the brutal physics equations seem to be conveniently ignored.

Perhaps there needs to be a day in driver's education courses where everyone has to review just how heavy a freight train is and how much kinetic energy must be dissipated in order for it to come to a complete stop. Maybe make them ride at the front of a train to experience how painfully long an emergency braking maneuver takes to complete.

Here in India we seem to have a large number of such ridiculously stupid people (perhaps a consequence of having a large number of people in general) but it also becomes a street-cred thing as someone in front of you beats the train at a railway crossing and now you look like a wuss if you just stand there and wait for the train to pass.

This kind of accident is so common I remember the government commissioning a series of funny PSA ads that played on national TV showing people acting recklessly at railway crossings, getting killed and then expressing their regrets from beyond the grave.

> I also find it amusing that all of the stories regarding train-car interactions seem to occur at crossings with modern signaling devices, rather than "at your own discretion" crossings in the middle of nowhere.

A large part of this is due to population density (or trip density) around the crossing. If you've got 1000x the number of trips on a crossing, a 100x safer crossing is still 10x more likely to result in a colission. Fill in your own estimates, as my numbers are clearly made up. Also, guidelines require more signalling in built up / dense areas, and at intersections with a history of colissions.

Additionally, if you have a colission at an unguarded intersection, the response is often to consider a guard, and if it happens again, the story is 'senseless officials refuse to put in guard' rather than 'sensless person disobeys guard and is injured/causes confusion and delay'

Be careful, as many topics in railway signalling, this is actually fairly complicated and tricky. As I said in another comment, crossings are pure evil. They are many hazardous scenario and without any system inside the car, mitigations are not fail safe.

Personnally, I belong to the school of « remove them all, whatever the costs ». A little extreme, but €&@% I hate these things.

In German written driving license test, there is a section literally dedicated for railway crossings.

Edit: Clarified that it is written test.

In my state of Georgia it was the only thing I failed on my driving test (we didn't have driver's ed when I a kid, you just practiced with your parents and then took one test). I yielded and looked but didn't come to a full stop. I remember it took 15 or 25 points off of my score, but since it was the only thing I failed, I still passed the exam.

The things is, I don't remember the written test I took having any content at all about railroad crossings.

> I yielded and looked but didn't come to a full stop.

Physics tells us that we should accelerate to spend the least amount of time in the danger zone (rail bed). Since the velocities are orthogonal, it doesn't matter if you are hit by a train when your car is going 55 or 5 MPH (probably, unless trees in the resulting vector of your now pulped car).

It never made any sense to me to see school busses stopping at a grade crossing, then taking an extraordinarily long time to cross those tracks. What happens if the engine fails while on those tracks and a high speed train appears.

No, my vote is to make sure you have a clear view of the tracks in both directions and punch it. Less probability of interacting with a train.

Thanks, 17-year-old me feels validated.
90 day license suspensions for those who ignore signals should do it.

Those that ignore the signals and live, that is.