TRAFFIC TOWERS- The next phase in the evolution of the traffic signal, was to employ the use of traffic towers. These came in a variety of shapes and sizes, with, or without electric signals mounted on them. This photo is of one with a signal atop built by the Yellow Cab Co. of Chicago. The date is 1927.
 

Here is another, more ornate example of a traffic tower. This one was located on the busiest corner of that time in the US...Fifth and 42nd St. in New York City. This tower was made out of bronze.
 

Some of the first signals took on interesting designs. The photo at left shows Los Angeles' early experiments with traffic control. Here, they used large rectangular panels that displayed red, yellow, and green. These signals were mounted on rather large, concrete pedestals that were equipped with flashing lights to fend off unsuspecting motorists. The center photo shows a message-augmented two color signal in 1927 Rochester, NY. The right photo shows another view of the early hand-operated semaphore signal.

Here's an interesting signal for you "multi-light" fans out there! Count 'em...7 lights on each of it's four sides! This signal built by the Novalux Electric Automatic Signal Company, a subsidiary of the General Electric Company, was pleased to introduce this "Safe and sane solution for the problems of traffic regulation." The signal could be operated by hand, and it was equipped with a hooded light at the top for protection of the officer operating it.

FIRST 4-WAY TRAFFIC SIGNAL

SALT LAKE CITY'S FIRST ELECTRIC SIGNAL
Lester Wire invented this version of the traffic signal in 1912. It was installed on the corner of 2nd South St. and Main. It was made of wood and metal with 8" "railroad type" lenses and was manually controlled. Interestingly enough, when this signal was retired in the early 20's, it was moved to Liberty Park and used as a birdhouse! No one knows of it's whereabouts today.
 

Here are three more versions of the traffic signal. A Seattle intersection is shown in the bottom picture, with both a conventional 3 color signal overhead and a traffic tower on the right. The top right photo shows a pedestal mounted two color signal with illumination at the top and warning flashers at it's base. This signal showed up in Detroit around 1923. The top left signal was called the "Attica Signal" built in 1924.It was used in Harrisburg, PA and had ten small and two large indications for traffic in both directions.
 

This drawing further illustrates the functionality of the Attica Signal. It featured countdown lights showing motorists how much time they had before the light change. Pedestrians only saw the red and green lights as shown in the right center drawing. The device also featured a cast aluminum case.
 

This photo shows a signal that was first installed in Long Beach. This "Banjo" signal has a disc at the top, in which an inner disc would rotate to reveal the messages along with a warning bell as the messages change. Lights would be employed at night.

Pictures of a model of this type of signal showing the legends and lamp colors. The bottom light was used at night for late night flash. This example also shows how ornate and fancy poles of the day were. Everything was made rather tastefully and aesthetically then.

This photo shows the Acme "semaphore" signals that were quite popular in Los Angeles in the 20's and 30's. When the signal would "change", a bell would ring and the flags on the side would exchange places via a synchronous motor. Also red and green lights were used on the head itself with a smaller light used for late night flash. The flag change took about 5 seconds. Acme signals did not have a yellow indication, as we know it today. When the signal changed, it would go red in all directions, for a few seconds. This would give traffic that was approaching the intersection a few seconds to clear the intersection, before the opposite street's signal turned to green. After dark, generally about 9:00 P.M., the arms would both fold in to the case. After that time, only the lights alone would operate.

Here is a photo of one of the last remaining "semaphore style" traffic signals. It is located in the Smithsonian Museum at Washington D.C. There is another interesting fact about these signals. At about midnight, or 1:00 A.M., the signals stopped working. At that time, the small flashers at the bottom of the signal came on. These small lights flashed late at night, when normal "STOP & GO" operation was no longer necessary. Typically, the yellow flashers were for the primary street, and the red flashers for the secondary street. When two major streets crossed, both streets had red flashers. If a street had yellow flashers, the signal post was painted yellow. If the street had red flashers, the signal post was painted with black and white "zebra stripes" as pictured above. (Additional information provided by David Morgan)

Another version used in San Francisco was the "Ghiglieri Signal" named for its inventor William Ghiglieri. It featured flashing red and green lights and earlier versions used a bell to help acquaint motorists and pedestrians alike of it's presence. This one was used on famed Market Street.

This is the "Wiley Signal", and became overwhelmingly popular in San Francisco. In fact, only recently did the last one of these parish into oblivion. Curiously enough though, these never caught on outside of the city. It used a eight sided cylindrical message in the top that would rotate between "STOP" and "GO" 45 degrees, and had a bell that sounded when it changed. One can still be seen in the Cable Car Museum downtown, and two are still used, although modified a bit, at Knott's Berry Farm in Buena Park, Ca.
 

Here is another version of the signal. This one was much smaller and was used in later years as a pedestrian signal. It featured 6" colored lenses that were embossed "STOP" and "GO". Notice the ornate controller cabinet next to this signal.  Signals and cabinets during the 30's and 40's featured "art deco" manufacturing styles. Tasteful and aesthetic!!

This is the "Darley Signal" and was used a bit later down the time line. Its claim to fame was that it only used two lights, and that the lenses on the right angle movements were swapped (i.e. green on top)! Because of this, it made use of embossed letters on the lenses with "STOP" and "GO" written on them. Other than the obvious, the other drawback this signal had was that there were no provisions for a reflector because of the design. This made it hard to be seen on bright sunny days. This signal along with it's 3 light younger brother were very popular in small town rural America. Crouse-Hinds was the other manufacturer popular around this time, and you can see a photo of this type in my "Signals" section. (Photo by Pete Yauch)