by boatsmate
Over the past several months I have seen on a few different occasions a yellow over yellow signal. I normally on see a yellow over red or red over red. the signal in question is the one just outside back bay tunnel on the CSX B&A Befroe Fenway. Then on thursday when I was headed home form work I saw another yellow over yellow, this time on a differnt signal. this one the signal right after CP4 facing the west on the track on the left (I was headed west on the Pike) and I am sure they where yellow not red.