Signal Material Transformation Period.

[thenetwork]

Who was the first traffic light company to revert to 100% plastic housings & lenses and when did it happen?

Who was the last traffic light company to stop producing 100% metal housings &/or glass lenses and when?

[DaBigE]

Who was the last traffic light company to stop producing 100% metal housings &/or glass lenses and when?

As far as I can tell, they still make metal housings and glass lenses are still available.

[Mdcastle]

Looking at the links you can even order glass reflectors!

Eagle might have been one of the first to produce plastic signals, the DuraSig line was introduced in the early 1970s when the aluminum "flatbacks" were dropped, later they reintroduced aluminum as the AluSig. My Mark IV (a successor company to Eagle) has a glass lens (A Kopp 4777 instead of the Kopp 88 as used in the flatbacks and earlier) which indicates glass lenses became available again too.

[M3019C LPS20]

With regards to your first question, I would also assume that Eagle first introduced its own line of polycarbonate signals. These appeared in the picture in the 1970s. Polycarbonate signals are still manufactured nowadays.

The next question is rather difficult to answer, since you have to realize that several signal equipment companies still manufacture aluminum signals. One fine example is General Traffic Equipment. The company continues to install its own 8" head for mainly the city of New York, and the mold is quite similar to Marbelite's model TE-19408 head. The company also has another 8" model that is similar in appearance to the 8" Eagle Mark 4 traffic signal. This model is in use in New York City as well.