While exploring the Somerville area today something came up I've been wanting to ask. Some of the grade xing flashers have a red plastic mask over the entire flasher. It forms a lens over the lights and sun visor. Kinda hard to explain but it's the same thing as those blackout plastic covers people put over their car headlights. There are a few scattered around Rt 22 / Somerville area. Anyone see these before? The are not 'new' as I recall them from the early 1980s when I worked in the area. Were these any kind of 'new' technology of the time or were they just a different manufacturer or something. Any info on why these unique ones were installed or a bit of their history would be appreciated.