Willis Lamm's
Traffic Signal Collection

Southern Autoflow
Traffic Signals Inc.
Southern Switch & Signal Co. of Shreveport, LA, produced a number of brands of traffic signals. Many of these manufacturers offered low cost 4-way signals from the late 1920s up into the 1960s that were ideal for small towns. Many signals had internal timing controls that weren't very sophisticated but were ideal for smaller, "stand alone" intersections. One company, Teeco Safety, still sells 4-way signals internally controlled or externally controlled, for use in replacing classic signals in historic districts.

  Internally Controlled Signals

Early traffic signals were principally controlled by one of four methods. They could be manually controlled by a police officer viewing the intersection, the intersection could be controlled a single 3 or 4 way fixed face head that contained a simple internal timer, single or multiple heads could be controlled by an external post or pedestal mounted controller or all signals could be wired back to a master controller that controlled a whole series of signals. Most early external mounted controlers contained very accurate 60 to 90 second clocks. Several signals in a row could be synchronized and remain so if the clocks all had the same time cycles and were periodically checked. Furthermore most early external controllers had manual overrides so traffic police could operate them manually when necessary.

Less expensive internally controlled signals were useful to small towns where "stand alone" (non-synchronized) signals were appropriate. The internal timing configuration was much less expensive although the timing was fixed at the factory and while the clocks were synchronous, they weren't as accurate as most external controllers. Nonetheless all a town had to do was connect power to an internally controlled signal to make it work and if a signal fell out of step with other signals, it could always be turned off for a few seconds and restarted so that it fell in sequence with other signals.

In this section we'll show the signals in the collection that have their own internal timers.

Note: Clicking on most images will bring up new or larger images on a new page.


Southern Autoflow was was a brand of signals produced by the Southern Switch & Signal Company of Shreveport, LA. There is evidence that the company probably started making signals in the 1920s. The earlier signals had four circuit timers which meant that at phase changes, yellow displays overlapped green.

In the 1950s and beyond, Southern Autoflow produced single faced signal heads and 6 circuit timers, including post mounted timers, that allowed independent yellow displays. Southern Autoflow typically used Kopp No. 66 diamond pattern lenses. The visors were attached by three permanent rivets.

Hinged door model Southern Autoflow
1930 Autoflow
1930 trade ads show Southern Autoflow's standard hinged door signal. Since older style Autoflow porthole style signals have also been found, it is likely that the portholes were first made in the late 1920s and may have continued into the 1930s for customers that still preferred the original porthole design.
Late 1940s Autoflow ad.
Here are some additional characteristics of the Southern Autoflow signal.

Classic art deco nameplate
Distinctive mushroom design weatherhead / hanger
Reflector assembly that hinges with the door
Kopp No. 66 diamond pattern lens.
The signal prior to restoration
Some early timing sequences were not real accurate. Yellow displays primarily meant, "Attention! The light is changing!" Ergo there wasn't such concern that lamps lit and went dark at precisely the right instant. You can view a video of the Autoflow's sequence to see what I mean.

Preparing to hang the signal

(The overhead haul line is attached to the John Deere Gator.)

The signal being used on the set of "The Man in the High Castle"

Continue to Sargent Sowell Traffic Signal

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