This may have been asked before but I'll just do it anyways. I've seen it in videos of people driving the M7 (Not sure about the M3 yet) and i wanna ask: why are there 2 separate panels for operating the doors placed on each side of the driver's cab? Add in the fact that the LIRR Route seems to be the only one that has those one track, surrounded by platforms...platform system, seems rather inefficient for the driver to have to stand up and walk to the other panel on the left side of the cab as opposed to having it on the driver's control panel in front of him. I know in TSW you could just press Tab and all but still though. I guess it makes sense if there's a guard with him ready to help him open the doors?
Adding onto what Anthony said, it's usually the conductor who has the keys and controls the boarding process at each station. There's a panel on both left and right hand sides that will open the doors on its corresponding side. Since the M7's are 2-car units in married pairs and there's a panel on either end of the pair, you have the ability to open the doors ahead or aft of the unit you're in. This is useful at certain stations like Forest Hills or Kew Gardens, where the platform is only long enough for 4 cars (as it is irl). The conductor can walk to the middle of the train, go to the cab end of the fourth car and utilize the panel to only open the doors ahead of where the panel is, and keep the doors closed in the other cars. That way the passengers don't just walk off the train when there's no platform. While it is a bit janky to perform, the whole process is doable and works just as it should in real life, it just might involve you flying the camera around to specific spots. I think you might be reffering to something called the Spanish Solution? You can read a bit more about it here. Essentially what this allows is for passengers to board using one platform, and for exiting passengers to use a different platform, thereby decreasing the amount of time a train dwells at a station. I think you'll see a few instances like this at Jamaica Station and at Penn Station, the two biggest stations on the LIRR. It's normal to have both left and right-hand doors open here. However you might encounter other spots where this might happen, like if you're being routed through the middle track at Hicksville Station. I think in real life they might open only the right-hand side doors since it's a small enough station with not too many passengers boarding or exiting. I don't claim to be an actual conductor/engineer however, just an enthusiast who's sharing what I've noticed. I hope this helps!
The conductor can be anywhere in the train and often move around from station to station. I don't remember seeing it on the LIRR but I know in the NYC subway that you sometimes see the conductor in the passenger area using controls in those cars. Paul
Most stations aren't dual platforms, so it makes sense that each door panel opens only the side its on, also preventing accidental opening where there is no platform by pushing the wrong button. For comparison, I don't think any stations on the Washington DC metro having dual platforms, but it works the same way. Many stations are left hand doors, so every station the driver parks the train, walks to other side of the cab and opens the doors, peeks out the window, closes doors and returns to move on to the next stop. Occasionally they have someone else in the cab, but mostly it's just the driver.
I know what is and have seen the Spanish Solution in my life but it was a strictly one platform for entry and one for exit so that's why i didn't think it would count for the LIRR since it seems you can board from both sides XD