Why Japan has blue traffic lights instead of green • Hacker News Board

Re: Why Japan has blue traffic lights instead of green

#81

Post by bluGill » Mon, Oct 23, 2023, 2:24 PM UTC

lozenge wrote: post #37

nemetroid wrote: post #27

Earlier quoted context omitted.

Horizontal lights are not consistent across countries. The linked article has an image of a Japanese horizontal traffic light with red on the right, whereas an American traffic light would have red on the left.

And some countries don't have horizontal lights at all. https://youtu.be/sXbHdKJ1D78

Which is even worse. I grew up in an area with only vertical lights. After several years of driving I ended up in an area with a horizontal light, one end was white and I had no clue if that meant stop or go. (I'm colorblind so I normally think top=stop, bottom=go)

Re: Why Japan has blue traffic lights instead of green

#82

Post by bombcar » Mon, Oct 23, 2023, 2:25 PM UTC

cafard wrote: post #64

mathieuh wrote: post #5

Earlier quoted context omitted.

Traffic lights are still fine for colour-blind people aren't they? The order of the lights doesn't change.

Almost fifty years ago, I worked with a guy who was color-blind. This was in Colorado, where at the time some of the little towns in the mountains still had traffic lights arranged horizontally rather than vertically. He must have known the order at one time--I think I learned it for my license test--but of course with little chance for reinforcement tended to forget. I suppose that such lights are all gone now.

They're common in at least four states still: https://www.youtube.com/watch?v=sXbHdKJ1D78

Re: Why Japan has blue traffic lights instead of green

#83

Post by [deleted] » Mon, Oct 23, 2023, 2:26 PM UTC

cthalupa wrote: post #57

Other people have covered the linguistic aspect enough so no need for me to rehash it, but, the picture in that article is far more blue than any traffic light I've seen in Tokyo in my months there. If I had to describe them with a single word, I'd choose green without hesitation - they just have a bit of a blue tinge to them. Some example photos from google image that look closest to what I've seen: https://www.pond…

[deleted]

Re: Why Japan has blue traffic lights instead of green

#84

Post by lewispollard » Mon, Oct 23, 2023, 2:26 PM UTC

troad wrote: post #50

yznlp wrote: post #29

Not a linguist. I feel like this is just an issue of imperfect correspondence between the word "blue" in English and "ao" in Japanese. The article explains the historical reason why ao encompasses both blue and green, so I think the concept of semantic field comes into play here. As an analogy, a MacBook is a type of laptop, and laptops, desktops and tablets are all IT devices (for lack of a better word). Apple might…

I trained as a linguist and you hit the nail on the head. Word meanings are fuzzy clouds of references and nuances, and every language has slightly different clouds. There is nothing magical about this, despite the recurrent lizard-brain notion that words or names are somehow mystical and intrinsic, and that these differences must somehow be meaningful. Differences are quite common with colour terms - you don’t need…

> it doesn’t actually matter what convention they pick, so long as everyone agrees on it and sticks to it.

That would be a good point, if that actually happened, but Japanese traffic lights have a mixture of green for go and blue for go (with most of them being green).

Re: Why Japan has blue traffic lights instead of green

#85

Post by bluGill » Mon, Oct 23, 2023, 2:29 PM UTC

acadapter wrote: post #4

Color blindness compatible design is, IMO, a very neglected part of the equality debate, in many other fields. This disability has a very skewed gender ratio due to how it works genetically.

Most green lights in the US have a blue tint so that color blind people can see the blue. Most but not all, which is really frustrating as a colorblind person. More than once I've been sitting at a light until my wife told me it was green as there is one light near me without that blue tint. (we are making a left turn so light has both the round red stop light and the green left turn arrow on at the same time)

Re: Why Japan has blue traffic lights instead of green

#86

Post by 2143 » Mon, Oct 23, 2023, 2:29 PM UTC

Just a data point that I want to put out there.

I have long heard that Japan has blue traffic lights.

Earlier this year I visited Japan.

Because I had heard about the blue traffic light situation, I paid special attention to the traffic lights.

They all appeared green to me. In both Tokyo and Osaka.

Okay maybe a tinge of blue if you look at it and wonder 'is this blue?', but the only reason I wondered was because I had heard the blue traffic light trivia. If I had never heard about it I wouldn't have given it a second thought.

However, the picture in the linked article seems to have an unmistakable blue color; I don't understand what's going on.

Beautiful country by the way; would love to visit again :)

Re: Why Japan has blue traffic lights instead of green

#87

Post by Finnucane » Mon, Oct 23, 2023, 2:30 PM UTC

omgwtfbyobbq wrote: post #15

mathieuh wrote: post #5

Earlier quoted context omitted.

Traffic lights are still fine for colour-blind people aren't they? The order of the lights doesn't change.

It depends on their kind of colorblindness. I see green lights as white, which is fine most of the time because of the order. The exception is when there's a lot of glare from the sun setting behind me, and I sometimes can't tell if it's green, or just the sun reflecting at the right angle. It also washes out the red and yellow, making it harder to see if they're lit.

I am the same--green traffic lights are nearly white. Normally, it's enough to know it's not the red or yellow light. Sometimes at night--face with an array of white lights in the distance--it can be an issue.

At my last eye test at the RMV, the clerk tried to tell me I wasn't color blind. I mean, sure, I've been able to drive with it for 40 years, but I know damn well I'm color blind.

Re: Why Japan has blue traffic lights instead of green

#88

Post by bluGill » Mon, Oct 23, 2023, 2:34 PM UTC

the_mitsuhiko wrote: post #22

mgaunard wrote: post #20

They speak of this as if it was a Japan-only thing. The blue-green distinction is a late feature of most languages. Even Greek and Latin did not have as clear a distinction as we have today.

> They speak of this as if it was a Japan-only thing. Which other countries have blue traffic lights?

The US. They are mostly green, but a lot of them have a blue tint for the colorblind. I suspect other countries as well, colorblindness is very common and this is a simple adaptation.

Re: Why Japan has blue traffic lights instead of green

#89

Post by selimthegrim » Mon, Oct 23, 2023, 2:36 PM UTC

woolion wrote: post #47

If you read any Chinese/Japanese literature, for example Buddhist or zen texts, it is very common to encounter very weird uses of the words blue or green-- because they mean things that somebody used to these distinct categories will classify nature according to these boxes. Trees are green, bodies of water blue -- even if that is more complex than that, some pines can be very blue, rivers or lakes can be much greene…

Do you have any examples of such Zen texts?

Re: Why Japan has blue traffic lights instead of green

#90

Post by NegativeK » Mon, Oct 23, 2023, 2:37 PM UTC

Prcmaker wrote: post #8

acadapter wrote: post #4

Color blindness compatible design is, IMO, a very neglected part of the equality debate, in many other fields. This disability has a very skewed gender ratio due to how it works genetically.

I learned this lesson in my first ever public lecture. Approximately 10% of my audience had some form of colour blindness, rendering the majority of my figures incapable of communicating their intent. Since then I have rendered all figures for public consumption in black and white, and lines instead of surfaces where possible.

I have the relatively typical male, minor colorblindness. Using color as an signal is fine, but just make sure there's something else that's independently conveying the info.

Also, another way to find out how common colorblindness is among your male friends: go rock climbing in a gym. Color is used on the holds to signify the route, and colorblind people who quickly start asking about color as they're climbing.