how would you escape from subway car trapped in tunnel? lets assume the train car derail but the train remain upright with no damage to the walls.

A few years ago, the Toronto train had serious accident which two trains collided with each other. The passengers had difficulty getting off the damage train by themselves.

These trains often have technical difficulty which cause them to get stuck in tunnel. I wonder how does one break open window if the emergency door opener is jammed.

"...I wonder how does one break open window...'

Having zero experience with those things, I can only wonder. Do they have tempered glass windows? If so, the usual spring loaded centerpunch will shatter one into a jillion pieces, and out you go. If they are other than tempered, you will need a Plan B...

The subway cars I've ridden on have push-out windows on some of the windows and a lever that will open the subway door. One or both should work; the windows are tough to break. One side of the tunnel (or bridge) is designed for evacuation, so you need to stay oriented to which side you need to get out on. In theory, there are emergency lights, but this is where you want your EDC light handy in your pocket. After you are out on the right side, then walk carefully, avoiding the third rail (hope power is off, but...), to the closest station/exit. Of course, one direction may be blocked or worse, have a fire.

Best advice I have is to take a close look at the system you are on and understand their own safety measures/rules. If they aren't obvious, ask....and modify your EDC kit accordingly; e.g., you may want something that could break open a window.

Does a regular glass breaker for car window work on train window?

A number of years ago there was a derailment & fire in the Mid Atlantic area. IIRC they had trouble getting the windows open w/ fire axes. A combination of laminated glass and firefighters were just able to reach the windows with axes overhead.

"Does a regular glass breaker for car window work on train window?"

No. The "glass" is not glass, but some type of plastic compound. Probably designed not to break so as to lower maintenance costs and "increase safety" (that is, avoid lawsuits from people getting cut on broken glass). If they were not, given the environment of people and places these cars go, there would be broken windows on every car every day.

I have no doubt that they could withstand blows from a fireman's ax.

Open the door?

If the carriage is lying on its side, you may have a problem. You can't open the door that the train is lying on, and the other door is now part of the ceiling and (in the UK) very heavy to lift. The doors that connect to the next carriage would be worth a try. If you have to break the windows, I'm not aware of any special technique beyond the usual.

At least in NYC, the "glass" is a plastic laminate over glass, and VERY hard to remove, mostly because in the 1980s (Pre-Rudy) the low lifes used to thing that kicking the glass out of the trains was "fun" - and it took a LOT of trains out of service

As for stuck in tunnel - if there is no fire etc - wait for the crew - what they will do is open the end door (front or rear - whichever is closest to a station), and they bring a small wooden staircase that is just high enough to go from the door down to the track bed - the MTA gets enough people to guide you out, and they do. A flashlight will be a help, as there usually isn't much light

I've seen it done, but never had to do it

is it legal for civilian to carry the glass breaker/seat belt cutter tool?

I'd be very interested to hear from people who have been evacuated from subway cars; either physically had to evacuate between stations, or had to sit in a tunnel for a while, then get delivered to a nearest station and left to find your own way home. I'm generally claustrophobic, so I don't like being on the subway, but as it's the fastest/cheapest way to get to work, I do it anyway.

I'd be interested to hear:
- what happened
- how did the train crew communicate with you, did they provide updates, etc.
- how long before you were able to evacuate
- how long it took from when the train stopped to when you were at a safe area (the next station)

I've certainly been in trains stuck between stations, usually with power, occasionaly without, but never forced to leave the station, only massive delays (most recently - the fire department was on the tracks in front of my train for some reason). I've thought about carrying my HT radio and earpiece with me on the train so I could eavesdrop on public transit and police/fire communications, but haven't since it would make my bag heavier than it already is, and would probably freak out both the transit police and my fellow subway riders.