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Derailing illusions that kill: misperceptions at railway crossings (2003)
- seesawtron 6y ago"One peculiarity of human perception is that large objects in motion appear to be moving more slowly than they really are" - Folks, never cross the roads/tracks when you see a vehicle approaching. Wait for it to pass and then cross.
- Jabbles 6y agoCrossing roads is different - and it would be often impossible if you had to wait until no vehicle was approaching. But as this article points out, you can't use your experience judging car distance/speed to judge train distance/speed.
- dredmorbius 6y agoSame applies to ships, especially for those in small craft.
- emmelaich 6y agoHow far away is the vehicle? How much time do you have? From a fairly recent HN article -- see Lamport's discussion of Buridan's principle. http://lamport.azurewebsites.net/pubs/pubs.html#buridan http://lamport.azurewebsites.net/pubs/pubs.html#buridan
- projektfu 6y agoI do notice some improvements in a few places over the last 17 years. Many busy highways now have overpasses. Many grade crossings have traffic lights as well. That’s good design in my opinion, like putting a stop sign bar on the school bus. I don’t know why grade crossings without gates do not also have stop signs. We have to assume that many drivers are unaware of the rules of the road, either through lack of training, forgetfulness, local culture, or inconsistencies with other countries.
- de_watcher 6y agoThe hell? Just put big automatic gates everywhere. Seems like a simple life/cost estimation exercise.
- paulcole 6y agoThink about the thing you know best. Imagine an article about a challenging problem related to that thing. A person with almost no knowledge of that thing reads it and says, “Seems simple enough” and presents a solution. Are they likely to have overlooked something? Misunderstood the problem? Be unaware of the challenges in solving it?
- misnome 6y agoBy my interpretation of the article, it seems to agree that this is the solution. The caveats seem to come mostly from paying for it.
- amelius 6y agoYes, but sometimes just bluntly stating a solution can be a request for enlightenment.
- drewzero1 6y agoCan we just put this comment on the top of every discussion here?
- a3n 6y ago"Why don't they just ..." https://blog.jgc.org/2012/08/why-dont-they-just.html?m=1 https://blog.jgc.org/2012/08/why-dont-they-just.html?m=1
- michaelcampbell 6y ago> Seems like a simple life/cost estimation exercise. All safety mechanisms are this. The tricky bit is the value of life calculus. Is it worth an added $10/year tax for every taxpayer to MAYBE save 1 life per 5 years? You'll get different responses for different reasons. That $10 may be a rounding error for many, but to some its the difference of a week of lunches for their kid or not, and they vote, too.
- LeChuck 6y ago> Even as the train moves toward you, and you move toward it, the train’s image maintains a relatively constant position on your retina[...] That's funny. The very first thing you learn on a ship is to watch out for exactly this. Any ship that maintains it's position relative to yours is on a collision course!
- deepsun 6y agoSame for pilots
- rhn_mk1 6y agoOr it's moving away from the same point.
- NovemberWhiskey 6y agoOK, fair enough: that's why they actually talk about CBDR - constant bearing, decreasing range.
- klodolph 6y agoThis is how old air-to-air missiles worked. They would steer until the image of the target stopped moving. This was something simple enough that you could make it work electronically in the 1960s.
- gruez 6y ago> This is how old air-to-air missiles worked. They would steer until the image of the target stopped moving. That seems to be a weird way of describing "steer so the target is always in center of the image".
- projektfu 6y agoNot necessarily on center. Constant bearing but decreasing range will result in a collision.
- davedx 6y agoIn the Netherlands there was a horrible accident a couple of years ago with children who'd been picked up by daycare staff in a small electric bicycle wagon where 4 of the children were killed. I still remember the feeling of reading the headline. Since then I've read that municipalities are accelerating the transition from railway crossings in urban centres to underpasses, despite the huge cost of this re-engineering. I think the problem with railway crossings is that they are just inherently dangerous, and the severity side of the risk equation if you get a crossing wrong is huge (potentially multiple people being killed). I like the Dutch approach here: replace them entirely. https://www.bd.nl/oss/vier-kinderen-4-tot-11-jaar-omgekomen-bij-ongeval-op-spoor-in-oss-twee-zwaargewonden-nog-in-levensgevaar~a22f10de/?referrer=https://www.google.com/ https://www.bd.nl/oss/vier-kinderen-4-tot-11-jaar-omgekomen-...
- brazzy 6y agoOh fuck, apparently the bicycle malfunctioned and couldn't brake. If only the rider had had the presence of mind to just steer sideways as hard as posible and take a roll instead... Edit: I'm not trying to but any blame on her. It's easy to think in hindsight of what could have been done, another thing entirely to do it in seconds while panicking.
- davedx 6y agoYeah of course, completely natural. My point is that even with all these insights into how human perception works, I agree with the strategy that it's best to bypass railways completely by going under/over them. And if it's doable in a densely populated country like the Netherlands then it's doable anywhere. (Some of the underpasses that have been built in recent years have required significant changes to the whole surrounding layout of the town, like one they completed in Bilthoven near Utrecht. Yet it was done.)
- mschuster91 6y ago> And if it's doable in a densely populated country like the Netherlands then it's doable anywhere. There's three different "doables" at play here: - technically doable: can you actually convert the level crossing to an underpass or a bridge? For example, it's hard to do an under/overpass when there is a river 10m away, or when everything bar the road/rail and a bit of space is filled with buildings. - financially doable: is there actually enough budget in the city/responsible authority's coffers? - politically doable: will the population support the necessary construction works and the limitations that come with it? Like, will there be heavy protests of people that rely on either the rail or the road to get to work and would require massive amounts of time to bypass? It is rare that there is a combination of all three being true, with the exception of course being tragic disasters with people and especially children dying as such events usually eliminate the political and financial blockers.
- pif 6y ago> The tendency to blame the victim in grade-crossing accidents exasperates cognitive psychologist Green: “That lets the authorities off the hook. Then they don’t have to redesign the system.” And why should they? Some people die, but how many times more people do cross successfully?
- mratsim 6y agoAnd then we have a nuclear incident because "everything we did worked for 30 years so we didn't do maintenance".
- rsynnott 6y agoI mean, you could say that of practically any safety rule. "Sure, some people die of cholera, but most don't, so continue dumping the sewage into the drinking water".
- sradman 6y agoRailway crossing design has parallels in software design. Rare events, expensive safety/security mechanisms, expensive redesign, and safety/security mechanisms that are perceived as repetitive irritants rather than timely helpers.
- rob74 6y 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!
- bob1029 6y agoI 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.
- archi42 6y agoTIL: "The rat is always right." //edit: okay, the above is a bit minialistic, so, in full: The article is a good point on how systems have to adapt to actual human (mis-)behaviour, instead of relying on wishful thinking on how humans should behave.
- Gravityloss 6y agoA hundred years ago, tradespeople were often missing fingers. For some reason, it was really hard to sell the idea of safer equipment. I bet it has something in common about hand washing in hospitals taking some hundred years to become mandatory - or how it was done much earlier in Hungary, yet nobody outside believed in it.
- chmod775 6y ago>The tendency to blame the victim They're only victims of their own stupidity. The real victims are the train drivers who are often traumatized, injured, or even killed in these collisions through no fault of their own. The same goes for other occupants of the car. Pretty much everyone but the driver.
- eloisius 6y agoThis article had lots of echos from The Design of Everyday Things. I highly recommend it if you haven't read it. Before I did "design" was a word meant mostly aesthetics with a little UX sprinkled on to me. This is 100% a design problem, and we have to design systems for people that are stressed, in a hurry, confused, think they are smarter than they are, you name it. The part about differentiating markings for active and passive crossings is especially poignant for me. I ride bikes a lot and cross numerous passive crossings on smaller country roads. It's not that I don't understand how those crossing works, but I'll admit that I often subconsciously think to myself, "they designed this not to kill me if I don't disobey the bells and gates" as I tear past it after a quick glance.
- Gravityloss 6y agoStyling is the word. It's different to design. It's only about looks. Design should be about functionality and ergonomics etc. In my native language, they still haven't really found out a satisfactory way to differentiate those.
- ghaff 6y agoOne thing I remember from that book that drives me crazy is the bit about push vs. pull door handles. You see handles that you intuitively pull on both the push and pull sides of doors all the time. (Our HQ building is one of them. I'm usually only there once or twice a year and I can never remember to pull or push the handles on both sides of the elevator core.
- happysadpanda2 6y agoIn a sane (or well-regulated) world, all doors would always open outwards, in the direction of the nearest exit. In case of fire, you don't want a horde of people pressing an inwards opening door shut
- ghaff 6y agoThey usually do and I imagine they do open out of the elevator core in this case (because the stairwells are outside the core). It's just not mentally intuitive (to me) that going "out" in this layout means going from the elevators to the offices. I'm sure it would be natural if I worked in the office but I don't so I need to think about it--or just do it wrong first :-) ADDED: And while "out" is obvious with an exterior door, it may not be with an interior door (and in fact there may not be a clear "in" and "out".)
- parliament32 6y ago>"The rat is always right." Green explained: "If you set up an experiment and the rat doesn’t do what you want it to do, it’s not because the rat is stupid, but because you set up the experiment wrong. It’s the same with humans." I think this is important to remember in our field too. Too often I hear about a user story breaking down because "the user wasn't doing it right".. blaming the user is the wrong way to go -- you just set it up wrong.
- globular-toast 6y agoReminds me of a story I saw on here about restaurant staff using a physical whiteboard marker to cross bookings off on the screen because the software didn't do what they want. Maybe someone can find the story (I can't). Users will always find a way to do what they need to do. The challenge is in finding out what they need to do because most of them would rather come up with their own solutions than come to the developers with a fully-specified feature request. I think this is why spreadsheets are so popular. They are never the best tool at any job, but users can bend them a million ways to do what they need to do.
- parliament32 6y agohttps://javlaskitsystem.se/2012/02/whats-the-waiter-doing-with-the-computer-screen/ https://javlaskitsystem.se/2012/02/whats-the-waiter-doing-wi...
- to11mtm 6y agoSome places just plain don't care what the end users want. The worst version of this is when you're stuck in a shop where features are very obviously only dictated by managers. You can usually tell this is the case when the manager insists on being a MITM for all communication.
- chongli 6y agoblaming the user is the wrong way to go -- you just set it up wrong. Sometimes the user is wrong. If a person drives their car into a lake and drowns, do we say that cars are broken because they allow this? Or do we point to the millions of other drivers out there and say that driving on roads (and not into lakes) is the expected user behaviour? An extreme example, sure, but I think it also translates to software. Some people criticize vi/vim for being modal because it confuses beginners. They use this as the basis of an argument that vi is a bad way to edit text or that modal interfaces are bad in general. But tons of other people take the time to learn the vi system of modal editing and they love it so much that they write plugins for everything else in an attempt to replicate that experience. Who is wrong here?
- Gravityloss 6y agoFor millions of years, the largest moving object humans had to deal was the size of an elephant. You can look at the time the object travels its length in and get some rough estimate of speed from there. You won't be mistaken that much. Now, take a 50 meter long airplane or 100 meter long train. Or a 300 m long ship. It's not going to work - fatal accidents ensue.
- dmckeon 6y ago> the traditional American crossbuck, the simple X-shaped railroad sign that warns drivers to yield to an oncoming train. I would guess that roadway signage in the US runs about 80:20 textual:symbolic, but that the EU runs about 20:80, with much heavier use of symbols, and use of text only to modify or explain something not covered by the available symbolic palette. Could any EU->US or US->EU migratory drivers make their own estimates?
- supernova87a 6y ago"How did you not realize that the empty circle means no parking from the hours of 1000-1600??"
- brnt 6y agoIs signage not in the driving exam in your locale?
- supernova87a 6y agoFor someone coming to a European country and driving by virtue of reciprocal driving license permission (not having to take an exam), those signs are not at all intuitive.
- brnt 6y agoThey're not meant to be intuitive, you're meant to learn them.
- janci 6y agoIn our country we have unprotected (sign-only) crossings, red light crossings without barriers, red light and barriers crossings and red-white light crossing (with out without barriers). The blinking white light informs the safety system is working and it is safe to cross. Unfortunately, they are actually removing the white lights to match the rest of the EU.
- potiuper 6y agoRed light crossings seem especially disadvantagous for red colorblind individuals with the addition of white light signals.
- jgeada 6y agoThis same set of perceptual illusion is the cause of one of the more common motorcycle crashes, colloquially known as the SMIDSY (Sorry Mate I Didn't See You) accidents: https://motorbikewriter.com/smidsy-biggest-cause-crashes/ https://motorbikewriter.com/smidsy-biggest-cause-crashes/ https://motorbikewriter.com/scientific-studies-explain-smidsy/ https://motorbikewriter.com/scientific-studies-explain-smids... Most drivers find it very hard to estimate the closing speed of a 2 wheeled vehicle approaching an intersection.
- neonate 6y agohttps://archive.is/Rynhm https://archive.is/Rynhm
- cs702 6y agoOne could say that these railway crossings are adversarial examples that trigger visual misperceptions in the organic neural networks inside our heads.
- mleonhard 6y ago> “Railroad crossing deaths in the U.S. have come down from 786 in 1975 to 315 in 2001. ... I think this was largely due to the U.S. government’s rail-highway crossings program which since 1978 has injected $4 billion into crossings improvements" Cars have become a lot safer in that time. And the number of crossings changed by a factor of 0.68. Both of these could account for the reduction in railroad crossing deaths.