I live in Northern Virginia, but travel to NYC enough to where it makes me ask, which mode of travel - car, train, or plane will get me from my door to Times Square the fastest. It seems fairly even, but I wonder how far one needs to travel for the plane to beat the train
A lot depends on how far you live from the airport or train station - I have a much larger "train is faster" radius because the airport is on one side of "the big city" and I am on the other - and there are train stations on my side.
The big difference is in the time to clear security and wait at the gate. I have read suggestions you arrive at the airport 3 hours before your flight. For domestic flights I go with 2 hours, even less when I know I can fast-track the lines, but that's up to you. For the train, you just need to get there before the train. The second difference is that airports are usually 30 minutes or more from downtown, while train stations are downtown - depending on where you're headed, that can be a big deal. I count that as another hour's time in the train's favour. And finally, there is a fair amount of "ceremony" in the actual departure and arrival of a plane - safety speeches and checks before departure, taxi-ing, waiting for takeoff, possible circling of the airport on arrival, more taxi-ing, waiting for the ground crew - that can add up to another hour.
For me, the train has a five hour headstart on the plane, because on top of all that I can get to the train station quicker than the plane, and it's already partway to my destination. That means I can go about 400 miles before the plane would be faster. This covers a fair amount of where I need to go, so I take the train quite often.