National Boards > Traffic Control

Origin of Mast-Arm mounted traffic signals

(1/7) > >>

WichitaRoads:
Pardon if this has been discussed before, but I will continue:

I was taking the long way home from church today, and stopped at what I believe to be Wichita's last permenant four-way head traffic signal installation on a span wire at Waterman and Hydraulic (http://goo.gl/maps/udn9P). If there are still others, I can't recall anymore. Anyway, it got me thinking - this was a pretty typical installation scenario for a long time. When did the use of mast-arms really take off? I've seen pics of two-light signals on mast-arms in NYC, but that seems to be really an exception of history.

When did they really take off? When and where was the first mast-arm installation that would be similar to the common modern use installed?

EDIT: I tend to think myself the 1960s in California... since I always seem images from TV shows at the time that have that typical Califonia mastarm with sun-visor look.

And as an aside, when was the first mast-arm used in Wichita? That may be a MUCH harder question to answer. :)

ICTRds

NE2:

--- Quote from: WichitaRoads on November 03, 2013, 04:06:00 PM ---And as an aside, when was the first mast-arm used in Wichita? That may be a MUCH harder question to answer. :)

--- End quote ---
Not necessarily, if you have access to good-quality old aerials and too much time.

dfnva:
That's an interesting question, but it may depend on the state.  I'm sure some states didn't use span wire at all, or rarely.  California  and Illinois come to mind as states where I've never encountered span wire except in construction zones, though I could be mistaken. 

In Virginia, span wire installations made up the majority of signal assemblies installed before the early 1990s. This time period marked a paradigm shift in using mast arms instead, though there were mast arms installed long before 1990.  Occasionally, permanent span wire installations are still erected in VA.  Most recently (2011 or so), a new span wire was installed by VDOT on SR-784/Dale Blvd in Dale City at a fire station.   

myosh_tino:

--- Quote from: dfnva on November 03, 2013, 09:30:36 PM ---I'm sure some states didn't use span wire at all, or rarely.  California  and Illinois come to mind as states where I've never encountered span wire except in construction zones, though I could be mistaken.

--- End quote ---

There used to be a span wire signal at the intersection of Foothill Blvd and Voss Ave in Cupertino, CA but it was removed more than a decade ago and replaced with a modern mast arm.

mrsman:
I think you are correct that California was probably one of the first areas to incorporate the mast arms in the 1960's.

From my observations, based primarily on pictures since I was born in the 1970's, in Los Angeles:

Before traffic lights, traffic in busy intersections were controlled by policeman who stood at the middle of an intersection and in some cases there was a special tower for them. 
traffic lights in the 1920's were primarily placed right in the center (where the policeman previously stood) red/green light with stop/go bars that would come out and an audible ding each time the light changed.
In the 1930's the same type of traffic signal were moved to the corners.  Now two lights faced every direction and by moving the signal away from the center, there was a smaller likelihood of a car running into the signal.
By the late 1930's the stop/go bars were eliminated and soon afterward the yellow light was introduced.

In the 1950's, most traffic lights were 8-8-8, two signals facing each direction, one on each opposite corner.

By the 1960's, the standard L.A. operation was seen.  On narrow streets, two 8-8-8 signal faced the street on poles.  On wider streets, an 8-8-8 signal was on the left side on a pole or on a streetlight.  On the right side, there was almost always an 8-8-8 signal and a guy wire mast arm.  The mast arm held a 12-12-12 signal.  Pedestrian lights also started to come on the scene at this time.*

It seems to me that the mast arms were introduced when the red cars and yellow cars (trolleys) were finally removed from the city streets.  The guy wire mast arms would've probably interfered with the overhead electrical wires.

Tubular mast arms came on the scene in the 1980's.  Many of the 8-8-8 signals were replaced with 12-12-12 in the 1990's, but plenty of the 1960's standard light exist, particularly in the San Fernando Valley.

* During my childhood in the '70s and '80s practically all city of Los Angeles traffic signals had pedestrian lights all around the intersection.  But Beverly Hills and Culver City were a little different.  At an intersection of a wide street with a narrow street (e.g. Wilshire and La Peer), there was a pedestrian light for crossing the wide street, controlled by a push button, but no pedestrian light for crossing the narrow street.  Beverly Hills had no guy wire to speak of, all of their mast arms were tubular.  Culver City traffic lights had guy wire, but they made heavy use of 12-8-8 on the mast arm.  As far as I know, all of Culver City's signals have been modernized, but at the corner of Sawtelle and Overland there is a flashing red light that is set up like the old traffic lights.

https://maps.google.com/maps?q=W+Washington+Blvd,+Culver+City,+CA&hl=en&ll=33.995208,-118.390379&spn=0.002343,0.00327&sll=38.804821,-77.236966&sspn=3.171762,6.696167&oq=washington+blvd+cu&t=h&hnear=Culver+City,+Los+Angeles+County,+California&z=19&layer=c&cbll=33.995208,-118.390379&panoid=NW5U48CZfN9DLg3ya_yjXw&cbp=12,239.68,,0,-9.08

Navigation

[0] Message Index

[#] Next page

Go to full version