3M M-131 Traffic Signal in Detail

My original video on the 3M signal proved much more popular than I could have ever dreamed so I finally got around to putting this sequel together. While the first video simply showed the signal cycling while I narrated, this one pulls the signal away from the wall and shows you everything.

From the lamp door to the visors and everything in between, this video shows you all that makes the 3M M-131 special.

Category:

Science & Technology

Tags:

• 3M
• HVS
• high
• visibility
• traffic
• signal
• light
• in
• depth
• detail

[RJSchex]

This particular signal, I'm presuming, was most likely made some time before 1978—I could tell by the 3M "Plumber's Gothic" logo on the back. It was in 1978 that the current 3M logo (Helvetica Bold) came into use.

[deloreanman14]

@RJSchex - Actually, 3M dilly-dallied on updating the logo on the lamp housings until the mid-90s, probably due to the cost of redesigning the molds. The build tags and several other parts of the signal sport the current, bold 3M logo. YouTube user SignalKid and I have come to the mutual agreement that mine hails from the early 90s, probably '91 or '92.

[deloreanman14]

@Sobek79 - The arrow lenses had the same fresnel design but with an arrow shape cut into a black shroud that covered most of it. There were pedestrian signals made but from what I've seen, they weren't too popular, probably due to the exorbitant cost. There was one in the City of Portland but it was removed from service before I could capture it on video.

[Sobek79]

@deloreanman14 I see. I know a lot more. Thank you.

The masks for arrow etc.. go behind the colored screens?

Was there a pedestrian signal of 3M?

[deloreanman14]

@Sobek79 - No problem. They were painted according to the standards of the jurisdiction that ordered them; Hunter Green, Black, or Yellow. Some are a combination like yellow body with black visors but most are (or were) all one color. The City of Portland used Hunter Green signals for years but has since switched to black. No smaller sizes were made (all were 12") although 8" adapters for standard signals were made but suffered from design defects so not many remain. Feel free to message me.

[Sobek79]

@deloreanman14 Thanks for the information. I thought they have always a yellow housing instead of green.

Was there a smaller or bigger version of this signal? I mean with different lens diameter?

[deloreanman14]

@Sobek79 - Back in the day before LEDs became commonplace, they were fairly useful at combating sun phantom, a phenomenon where all three indications appear lit at once when the sun enters the lens and reflects off the interior reflector plate. These are also useful if you have an intersection where only a certain lane or lanes should see the signal. They can be fitted with backplates; if you look closely at the side profile, you'll see screws in the center of each section to affix a backplate.

[Sobek79]

Very interesting video. What isthe advantage of using a 3M signal over a more "common"signal?

Did those signals have a backplate?

[GrnArrow092]

Of course, you were quite lucky to get yours brand new and at a steal for $25. I paid something like $100 plus shipping on ebay.

[GrnArrow092]

I bought mine back in 2003 from California. This signal had seen a lot of wear and weathering over the years. Since 3M no longer makes the PV signal, I've considered ordering a case of olive green paint to give the signal its original California color. I haven't been satisfied painting it anything other than olive green since California is where it came from.