Traffic Lights?

[keiman]

Question for our current Japanese residents/Visitors.

The sequence including colours of traffic lights - what is it,are they 3 colours, also do the Japanese have sets of portable lights similar to those used in the UK at road works?

http://www.google.co.uk/search?q=traffic+lights+sequence&hl=en&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=90-6TrSgBY6F8gOb5cG_Bw&ved=0CFkQsAQ&biw=1024&bih=649&sei=%20ElC6Tqr3AcfT8gOzrKTTBw

 

A lot of questions I know but am thinking of using some 3 aspect signals for this as an experiment, useful circuit on the link- thinking could build the electronics easily if I can source all the bits.

[westfalen]

I've seen the portable lights at roadworks. The ones in Japan give you a countdown until they turn green.

 

Now that you ask, I'm not sure of the sequence but Japanese traffic lights are usually horizontal rather than vertical.

 

I'll have to look at some more closely tomorrow.

[ToniBabelony]

There are standard sequences (blue - yellow - red - blue - yellow - red, etc.), but also some strange combo signals. Well, not strange in a sense that they are incomprehensible... Take a look at this video and you'll see what I mean.

 

[Densha]

I didn't know Japanese traffic signals were so weird, I don't really get them. So they basically never turn green, there will always will be a light on to give permission to pass (don't really get why they would do two red signals and those other weird combos), and at last there are signs that give the direction.

[Bernard]

There are standard sequences (blue - yellow - red - blue - yellow - red, etc.), but also some strange combo signals. Well, not strange in a sense that they are incomprehensible... Take a look at this video and you'll see what I mean.

 

Thanks for this video.....now I know to never drive in Japan....

In the USA the traffic signal system goes like this: Red means Stop, Green means Go and Yellow means Go Faster. 

[Densha]

Thanks for this video.....now I know to never drive in Japan....

In the USA the traffic signal system goes like this: Red means Stop, Green means Go and Yellow means Go Faster. 

That's the same as almost everywhere in the world, as in The Netherlands where I live.

[keiman]

Toni :

Thanks for that video, makes me think maybe not such a good idea of mine. found some 1.2 mm LEDs I was going to try.. That shows you really need serious P.I.C programming to built a circuit to replicate those sequences.

Bernard:

I agree with your comment. other thing with yellow you missed check mirrors for local Law enforcement behind you and camera's on the lights- instant fine thro the post if changed to Red as you cross at those b****rs over here.

[Darklighter]

I guess those strange sequences are pretty rare.

In this video:

everything looks pretty standard to me.

[Densha]

That could be only around Sendai, and different at other places (like small rural places). All signs and lights had the same design, so they possibly wanted to have an entity to make it more efficient and so on. I'm curious if that place is still intact or not because of the tsunami. I really like having signs above the road instead of next to, it's much clearer which belongs to which driveway.

[Mudkip Orange]

I don't see where this is too dissimilar from the US.

 

Here we have the "doghouse" signal which can display a protected left at the same time as a red ball which prohibits other movements. Houston has a variant where the left turn is a green ball instead of an arrow, which means left turns have to yield to oncoming traffic. We've also got a lot of separate left turn lanes that will display a red ball while the adjacent lanes show green for through and rights.

 

As near as I can tell the Japanese are just more exact with the protected-prohibited combinations, in the video you have a red at the top (prohibits movement) and then it's modified with green arrows that specifically allow straights, or straights and lefts, etc.  If anything this is slightly more logical, especially if you don't have a separate lane for every movement. Less space in Japan for six-lane arterials with dual lefts like suburban Maryland.

 

The one at about 41 seconds in, that's just saying you can't turn. In the US this would be a combination of a standard green ball plus either a textual "NO TURNS" sign or two signs with the pictograms for "no left turn" and "no right turn." Which is better? I dunno. Suppose it depends on whether you're a light bulb manufacturer or an aluminum manufacturer.

[Mudkip Orange]

Chapter four of the MUTCD has all of the standard face arrangements for signals:

 

http://mutcd.fhwa.dot.gov/pdfs/2009/part4.pdf

 

You have to scroll about 40 pages in to get to the pictures. This doesn't include the aforementioned Houston green-ball-against-red-ball, the Pittsburgh or Rochester systems, or other regional variants - this is just the federal standards that are approved for use anywhere.

[bikkuri bahn]

Move this thread to scenery?

[KenS]

That could be only around Sendai, and different at other places (like small rural places). All signs and lights had the same design, so they possibly wanted to have an entity to make it more efficient and so on.

 

Not just around Sendai. A quick flickr search for "japan traffic light tokyo" turns up a  number of the simple three-light signals as well as sets of six-light signals (probably for turning lanes) like this one.

 

BTW, the Sendai-Moroika drive video was really cool.  It's interesting how similar the roadside looks to many places in the U.S. with suburban sprawl (right down to the Shell gas stations).  Aside from the occasional bit of architecture (which probably wouldn't be out of place in California) and the Japanese text on signs, it looks a lot like New England.