OK, so what is the official name (if there is one) of the things, over traffic lights under some overpasses and short distance intersections, that have little shades going downward, to shade out the light until you're right under it? There's several around Angelo and I don't know what they're called....
BigMatt
You mean something like these:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fsafety.fhwa.dot.gov%2Fintersection%2Fredlight%2Frlr_report%2Fimages%2Ffig312.jpg&hash=06568ea1ba2fb890cf04b73bdbdd1c1d469a4472)
(from the FHWA website)
They're called louvers and they are used like how you said the shield the signal from viewed in the other lanes. There's a few here in Toronto for the streetcars and buses and for some interections.
Hope that helps.
Thanks!
BigMatt
An alternate to the louvers are the older 3M signal and the new McCain Programmable Visibility heads...
3M:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Flh5.ggpht.com%2F_ZkmN2RrOJxw%2FSzOdKiUrVBI%2FAAAAAAAASIU%2FV-NQEKMV4s4%2Fs640%2FIMG_1457.JPG&hash=6dc7234cb7d4e067541e54526031d342abfb520d)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Flh5.ggpht.com%2F_ZkmN2RrOJxw%2FSzOdKbrYBhI%2FAAAAAAAASIQ%2FxqGNLmUjizI%2Fs640%2FIMG_1455.JPG&hash=72a51c891d7ad20f14885b6131123e986b6ad146)
McCain:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Flh5.ggpht.com%2F_ZkmN2RrOJxw%2FSZOLrkc_-TI%2FAAAAAAAADLk%2FO4VeoH4eARk%2Fs640%2FIMG_1814.JPG&hash=5e957eb2d409238671fc2f4e54f2e5b81a3a6bd9)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Flh4.ggpht.com%2F_ZkmN2RrOJxw%2FSeKExGzhF3I%2FAAAAAAAAFeI%2Fy83Uq_XDr34%2Fs640%2FIMG_3167.JPG&hash=2f7a231bb3389b718a8250df33487224db22f082)
Quote from: PennDOTFan on April 26, 2010, 10:51:27 PM
An alternate to the louvers are the older 3M signal and the new McCain Programmable Visibility heads...
IIRC, it's the MUTCD itself that says to use louvers instead of programmable signals. The problem with the progs is that while they do shield out the other movements, they're far too hard to see for the intended movement. You can't tell what the signal is showing until you're almost right underneath it in most cases. And if you're on one side of the lane at a very slight angle, you may never see it turn green.
Quote from: AlpsROADS on April 27, 2010, 08:02:15 PM
Quote from: PennDOTFan on April 26, 2010, 10:51:27 PM
An alternate to the louvers are the older 3M signal and the new McCain Programmable Visibility heads...
IIRC, it's the MUTCD itself that says to use louvers instead of programmable signals. The problem with the progs is that while they do shield out the other movements, they're far too hard to see for the intended movement. You can't tell what the signal is showing until you're almost right underneath it in most cases. And if you're on one side of the lane at a very slight angle, you may never see it turn green.
Does it really say that? Does that mean no new programmable heads are allowed to be installed? This is news to me, even though I have found that the new Pelco high intensity louvers have a better effect. Here is a pic of those Pelco louvers and how well they work:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Flh4.ggpht.com%2F_ZkmN2RrOJxw%2FS9eOGdPbzpI%2FAAAAAAAAaqE%2FDgOcLPWCveU%2Fs640%2FIMG_8162.JPG&hash=5744fe8e150e03ef25c9107a5e1e4a0a4ca324fd)