Blue light, Green line

So by every door on a type 7 or 8 green line car there is a little red light that goes on when it's open. By the front door there is also a blue light. What does this light signify? I rarely if ever see them used. Something tells me it doesn't mean blue light special on the green line half price...

The blue light is actually a fault light, signifying a problem with the car.

I think the red lights above the doors are just indicatior lights to tell the opperatiors and people trying to rush to get in, that the doors are open. I believe they blink and make a sound now when closing

I'm No Green Line expert..


But Red light near the doors are known as Pilot Lights they tell the train crew when they on, the doors are open or ajar. The train cannot move if the Pilot is on because this lights is part of the no motion system and cuts out the propulsion system.

The Blue Light is part of the propulsion system unrelated to the doors, But if the train has a blue light it means the propulsion on that car is dead until the light is put out or given reset. Hopefully you will never see a blue light on but if you do you can be sure that car will be coming out of service fairly soon.

The Blue Light signifies the propulsion is blown or a set of propulsion is cut out on the car. It is the same for the rapid transit too.

GP40MC 1116 wrote:I believe they blink and make a sound now when closing

I have never heard a light make a beep before!

The door's closing on the 3700 - 3800 "S ADA provision.