A Spotter’s Guide to Traffic Signals: Part 2

This is part 2 of the spotter’s guide to traffic signals. In the previous part I covered early Eagle Signal products. This second part continues with their later products and “everybody else”. Once again, I’ve noted “enthusiast / collector slang” by parenthesis to avoid confusion with official designations for products.

Later Eagle models

In 1987 Eagle was bought by a company called Mark IV Industries. Shortly before this Mark IV had also bought out Automatic Signal. Each company had 8” and 12” vehicle and pedestrian signals in poly and aluminum, so a total of 24 products, so simplification was inevitable.The following products survived the merger:

  1. Eagle Alusig, 9″ pedestrian only as type SA, later discontinued
  2. Eagle DuraSig, 9″ and 12″ pedestrian and 8″ and 12″ vehicle as type SA
  3. Automatic polycarbonate, 8″ and 12″ vehicle as type SIG, 8
  4. Mark IV aluminum, 12″ pedestrian and 8″ and 12″ vehicle as type SIG, 8″ vehicle later discontinued.

“SIG” is known as “SG” with LEDs, and now can only be ordered that way. Of these types, SA continued to be used in the cities, while Mn/DOT and the suburbs switched to aluminum SIG exclusively, (referred to by enthusiasts as “Bubblebacks”). Mn/DOT finally switched to polycarbonate a few years ago, and suburban agencies followed, so now we’re starting to see type SA in the suburbs.

Siemens bought Mark IV’s signal products in 1997, discontinued the Eagle name, and moved Eagle away from the Quad Cities to Texas. In 2013 Siemens sold Eagle’s signal head business to a company called Brown Traffic (while keeping the more profitable control business). Brown has indicated they plan to re-introduce the Eagle name, and update the molds to the new Eagle logo, which is a realistic perched eagle rather than the stylized “Thunderbird” of the past 50 years. The headquarters has returned to the Quad Cities, although manufacturing will likely stay in Texas.

Type SIG "Bubblebacks, later version, 98th and Dupont Ave / I-35W, Bloomington.

Type SIG “Bubblebacks, later version, 98th and Dupont Ave / I-35W, Bloomington. Eagle visors tend to point downwards more than other brands.

Early Bubbleback before the logos on the backs were removed about the time of the Siemens buyout. After this the backs were unmarked and there was "EAGLE" spelled out on in small letters on the top where it's impossible to see from the street.

Early Bubbleback before the logos on the backs were removed about the time of the Siemens buyout. After this the backs were unmarked and there was “EAGLE” spelled out on in small letters on the top where it’s impossible to see from the street. From my personal collection

 

Econolite (and GE) Products

Econolite is based out of California.  They’re most noted by enthusiasts for producing a line of neon pedestrian signals that were ubiquitous in California (now virtually all gone), as well as distinctive looking vehicle signals. They got into the vehicle signal business in the early 1950s when General Electric, one of the early players, changed their design and sold them their old molds (In 1957 GE would exit the business entirely and sell them the remainder). I’ve seen 1950s-early 2000s Econolite products used here; there are some in St. Paul, but they tended to be used more in the suburbs.

GE, and later Econolite 8” signals were rather distinctive in that there were vertical grooves running down the back.  A late 1950s production change was to shorten the grooves so they didn’t go all the way to the end of the section due to water ingress problems. Enthusiasts refer to these as “Groove Back”, “Long Groove” and Short Groove”. The corresponding 12” signals were circular and had a concentric design, “bullet backs”, and could come with either round or square doors. (Econolite models numbers were E31 for 8″, T31 or ST31 for 12″, and C35 or SC35 for a combination, the “S” denoted square doors rather than round) These designs lasted until the early 1980s, when “Buttonback” 12” signals debuted. “Buttonbacks” lasted until the early 2000s. These were the last Econolite products I’ve seen used here.

This is the only piece of GE equipment I've seen in Minnesota, a long defunct flasher on Vermillion Street in Hastings.

This is the only piece of GE equipment I’ve seen on the streets in Minnesota, a long defunct flasher on Vermillion Street in Hastings.

Pair of GE signals in Heritage Square at the Minnesota State Fair. In the 1940s GE signals came with beautiful "Spiderweb" lenses. With Heritage Square demolished I don't know the fate of these.

Pair of GE signals in Heritage Square at the Minnesota State Fair. In the 1940s GE signals came with beautiful “Spiderweb” lenses. With Heritage Square demolished I don’t know the fate of these.

8" back styles for GE, left; early Econolite, center, and later Econolite, right.

8″ back styles for GE, left; early Econolite, center, and later Econolite, right. From my personal collection.

Econolite "Bullet back" and "Short Groove" signal, 7th and Montreal, St. Paul.

Econolite SC35 “Bullet back” and “Short Groove” signal, 7th and Montreal, St. Paul.

Econolite "Buttonbacks", Market Drive and Curve Crest Boulevard, Stillwater

Econolite “Buttonbacks”, Market Drive and Curve Crest Boulevard, Stillwater. These are very rare here, and later Econolite products (which look much like the McCain signals described below) are not used at all.

Econolite "C35" (actually pieced together from different lights, along with an Econolite E8 neon pedestrian signal, this configuration was iconic of California for decades.

Econolite “C35” (actually pieced together from different lights), along with an Econolite E8 neon pedestrian signal, this configuration was iconic of California for decades. From my personal collection.

This setup in operation.

McCain Vehicle Signals

In the past decade or so McCain polycarbonate signals have been showing up. They’re very plain looking, but they do the job. 8″ models are often used  as ramp meters. Except for a smaller size they are identical.

McCain 12" vehicle signals, County 10 and County H, Mounds View

McCain 12″ vehicle signals, County 10 and County H, Mounds View

Front view of a McCain 12" vehicle signal, Valley View Road and Flying Cloud Drive, Eden Prairie

Front view of a McCain 12″ vehicle signal, Valley View Road and Flying Cloud Drive, Eden Prairie

 

Programmable Visibility Signals

In their own category are “programmable visibility” (PV) signals for when it’s desired to only allow it to be seen from a narrow viewpoint, for instance two roads the meet at a sharp angle.

3M Model 131, introduced in 1969, was the first of this design. Rather than a conventional traffic signal bulb (which resembles a standard clear incandescent), these used a compact, high intensity PAR lamps that was accessed from the back. The light from the bulb went through a frosted diffuser, and then a clear optical limiter lens, followed by the acrylic tinted Fresnel lens in the front. The whole assembly could also be tilted at different angles. How it worked is once the light was mounted, you’d go up in a bucket truck and peer through the optical limiter toward the road, seeing an inverted image of the road.  You’d then put a special 3M tape (more or less heavy duty duct tape) on the optical limiter to cover parts of the road you didn’t want to see the light.

Front view of 3M traffic signals, Trunk Highway 121 and 58th St, Minneapolis

Front view of 3M traffic signals, Trunk Highway 121 and 58th St, Minneapolis

3M 131 internals, front view. The top section has the wire guard and diffuser in place, the bottom section has them removed.

3M 131 internals, front view. The top section has the wire guard and diffuser in place, the bottom section has them removed.  The white object in the background of the bottom section is the lamp. Normally there would be a pole adapter on bottom, which I removed to make it sit flat on a table. Also missing is the dimmer, which would fit on the lower left. These would automatically dim the light at night, but were stripped out during LED conversions as they were not compatible.

3M 131 internals rear view. Top: bulb removed, diffuser present. Bottom: Bulb present, diffuser removed. This is masked so you can see it close-up but not farther away, as might be used in two intersections really close to each other. An LED retrofit bulb is on the table.

3M 131 internals rear view. Top: bulb removed, diffuser present. Bottom: Bulb present, diffuser removed. This is masked so you can see it close-up but not farther away, as might be used in two intersections really close to each other. An LED retrofit bulb is on the table.

Eventually McCain introduced their own PV signal to compete directly with 3M. They looked similar, except for the back (which is actually a re-purposed 8” section) and using standard circular visors. This area was never enthusiastic about them, preferring to support the local company. However competition and declining orders eventually led 3M to discontinue their model in 2007 so for a while McCain was the only PV option.

McCain PV signals, Calhoun Pkwy and William Berry Dr, Minneapolis

McCain PV signals, Calhoun Pkwy and William Berry Dr, Minneapolis

As a more modern  alternative, a company called Intelight offers “electronically programmable” signals. Basically rather than a few high powered LEDs as used in most signals, there are a large number of standard LEDs in a grid. These can be selectively disabled through software to restrict the visibility, generally done by a smartphone app by a worker in the street. These have large heatsinks on the back and so are hard to mistake for anything else.

Intelight fronts, Franklin Ave. and East River Parkway, Minneapolis.

Intelight fronts, Franklin Ave. and East River Parkway, Minneapolis.

Intelight backs. Franklin Ave. and East River Parkway, Minneapolis

Intelight backs. Ave. and East River Parkway, Minneapolis

 

This concludes the spotters guide. I’ve left out products by a number of companies that have only a miniscule share of the equipment here, but what I have have included amounts to well over 99% of the equipment in service here.

Streets.mn is a non-profit and is volunteer run. We rely on your support to keep the servers running. If you value what you read, please consider becoming a member.

7 Responses to A Spotter’s Guide to Traffic Signals: Part 2

  1. Reuben Collins
    Reuben Collins July 28, 2014 at 9:49 am #

    Great post! What do SA and SIG stand for?

    • Monte Castleman
      Monte Castleman July 28, 2014 at 10:09 am #

      I was kind of ambivalent about whether to include official model numbers. I felt I should to be complete, but they’re never used by enthusiasts and collectors, and the slang is more descriptive of the actual lights. I don’t know if they have any meaning beyond arbitrary designations- the “I” in “SIG” seems to retroactively mean “Incandescent”, but the model was designated well before the LED era.

  2. Bill Lindeke
    Bill Lindeke July 28, 2014 at 10:44 am #

    This is way more interesting than it has any right to be. I’ve always been curious about different ‘pedestrain walk men’, as per this guy: http://blogs.wsj.com/scene/2013/10/15/what-do-pedestrian-traffic-icons-say-about-your-culture/

    • Monte Castleman
      Monte Castleman July 28, 2014 at 11:02 am #

      There’s actually a couple of Canadian standard “Walk Men” around Eden Prairie Mall.

      • Matt Steele
        Matt Steele July 28, 2014 at 11:18 am #

        Doesn’t St. Paul use the “walk men” in some spots too?

        • Monte Castleman
          Monte Castleman July 28, 2014 at 11:44 am #

          If you’re referring to Canadian style, I’ve not seen them in the city of St. Paul. Both cities went out and changed out all of their pedestrian signals a while ago. Minneapolis scrapped all the dual 9″ housings and replaced it with a single 12″ “overlay outline” LED module. These are no longer allowable, so as they went bad they started to be replaced with “solid” modules, and then, since a single 12″ can’t accommodate a countdown, with new 16″ housings.

          St Paul kept their existing housings, but replaced the “Don’t Walks” with an solid LED “Hand”, and kept the Walks incandescent but swapped in a plastic “Man” lens. St. Paul used dual 12″ housings on some major streets, and these have been retrofitted to countdowns with the numbers in one segment and an overlay module in the other. They can’t do that with dual 9″, so those are being replaced with 16″.

          Canada still allows outline modules, and many of them are 12″ circles. The “Hand” looks similar but as noted the “Man” is a bit different.

  3. Red July 29, 2014 at 2:17 pm #

    Saint Paul does indeed have a few signs that are not the standard “walk man” — I’ve seen them in the area near Landmark Center / Saint Paul hotel.

Note on Comments

streets.mn welcomes opinions from many perspectives. Please refrain from attacking or disparaging others in your comments. streets.mn sees debate as a learning opportunity. Please share your perspective in a respectful manner. View our full comment policy to learn more.

Thanks for commenting on streets.mn!