Gallery of Lights
Lanterns/Fixtures => Traffic Lights => Topic started by: dor123 on January 12, 2011, 11:37:17 AM
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In the US and Canada i noted that there is a massive installations and usage of an exceptional type of traffic lights that aren't exist in any another location in the world: The four way traffic lights.
It is a traffic light that have signals in all of its 4 directions, so its lights are visible from any direction.
I don't know of any type of four way traffic lights outside North America, and even in Israel, we have no four way traffic lights.
Why this is the case?
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Depends on what you mean by four way. Traditional four way signals were only produced from the 1920s till the early 1960s. These had all four directions rolled into one body. Common in small towns back in the day that just wanted one light hanging in the middle of town in the 1940s and 50s mostly. Four ways were phased out for the adjustable signals, which are regular signal heads.
To create the four way cluster that is common today four adjustable signals are mounted on pipe bracketry and directed four ways. They are referred to as adjustable because the heads can be turned slightly on the bracket for intersections coming from other then right angles. Standard four ways are fixed since they're all part of one body.
It proved to be more economical to cease production on traditional four ways and focus on just adjustable four ways and signals. The only producer of a fixed four way in business today is Teeco. Teeco's four way is only bought by small historic districts to keep the old signal look when the original old one becomes too worn out to operate.
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Similar "4-way" was used here, but was replaced ~50years ago by individual (for each road joining the junction) heads.
Reason was the confusion the classic hanging 4-way caused, when moved e.g. by wind.
Since then all signals are placed just before the junction, so as driver you see only those valid for the direction you are approaching from.
This is different in the US, where signals are mostly behind the junction.
I wonder why, as in my experience it may cause lot of confusion "what signal is actually valid for me?". The problem is mainly when two roads are joining at sharp angle from nearly common direction, when you are not aware of the second road, so you just see two sets of lights, both nearly facing your direction... And to note, then i (as a foreigner from Europe) was by far not the only confused there...
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@Medved: In Israel the signals are also placed before the junctions.
This is much better then the 4-way signals as used in the US and Canada.
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The one thing I don't like about signals being placed before the intersection is that it can be hard to see the signal if you're the first car at the intersection imho, over here our signals are arm mounted after the intersection, one on each side.
I've seen signals mounted before the intersection here too though in conjunction with the regular signals. They're used where the sightlines approaching the intersection might be poor.
I've never seen a four way signal here in Ontario even in pics from the '60s though. Maybe they used them at one point...
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Joseph, to compete with this problem, in juctions that the first drivers can't see the traffic lights, there are 4-4-4 traffic lights which are placed lower, to allow the driver to know the color of the traffic lights.
Here is an example. (http://www.galleryoflights.org/mb/gallery/displayimage.php?pos=-4226)
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Yeah but that adds unnecessary complexity to a intersection that can otherwise use two standard signals...
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What was customary here on two and more lanes were signals for the left lane (so on the direction divider) to be placed on the left side of the road. But it was one triplet extra and i guess the cost reason took care, then such "luxury" disappear.
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The one thing I don't like about signals being placed before the intersection is that it can be hard to see the signal if you're the first car at the intersection imho, over here our signals are arm mounted after the intersection, one on each side.
I've seen signals mounted before the intersection here too though in conjunction with the regular signals. They're used where the sightlines approaching the intersection might be poor.
I've never seen a four way signal here in Ontario even in pics from the '60s though. Maybe they used them at one point...
Joseph, btw, i noted yesterday (Saturday feb.6.2011) that the traffic lights in Israel, arranged in a different way from what i thought before: In many of the juctions and the pedestrian crossings with traffic lights in Israel, the traffic lights actually stands on BOTH before and after the junctions or the pedestrian crossings.
I saw this firstly on Saturday feb.6.2011 in Haifa.
Anyway, i found several examples of this arrangements in pictures on my traffic lights and signs album in my gallery on this site, and here is one of them: (http://www.galleryoflights.org/mb/gallery/displayimage.php?pos=-1107) In this case, in this Emeq Hefer settlements junction picture, you can see four traffic lights, while each couple traffic lights is for the same direction, in each couple, one traffic light is far from the driver then the other.
The close traffic lights located BEFORE the junction and the farther traffic lights located AFTER the junction.
In pedestrian crossings with traffic lights, the traffic lights arranged in the same manner.