While stopped at a railroad crossing in my A/T Honda CRV with my car in Drive and my foot on the brake; does my car eventually go into Neutral on its own if I'm there for while?
To my understanding, no. I've never seen this behavior before in any auto I've ever driven or read about. I think it would be a safety issue if it did. If you needed to move suddenly (for whatever reason), pulled your foot off the brake pedal expecting the car to move, and it does nothing but rev the engine at you. This could be extremely dangerous on an incline, as well. You would start rolling back. Your average driver would not know how to react in time.
I've driven a few automatic Opel Vectra's (2003 model) and they all had something of what you describe. The transmissions were somehow smartly adaptive to my recent driving style (sporty or cruising).
I also noticed that, when stopping briefly, they would respond immediately to the gas - but when stopping for more than maybe 20 seconds (and keeping pressure on the brake), they would sort of "open the clutch" and take longer to get going again. I believe that's a feature to protect the automatic clutch from undue wear.
So - it's not really "Neutral" but it seems to be like pressing the clutch in a stick shift, basically achieving the same effect.
The latest bmw's, and many cars using the ZF 8 speed gearbox (Jaguar XF, XE, most recent BMW's, and a number more) have an auto neutral feature.
Automatic idle shift system at vehicle standstill and engaged service break (stand-by control)
So, not your Honda, nor many automatic transmissions will shift into neutral on their own, but the ZF and many future ones will due to the need to increase efficiency.
All you'd ever like to know about the ZF 8 speed gearbox, and what it is used in can be found on Wikipedia, https://en.m.wikipedia.org/wiki/ZF_8HP_transmission
It is very similar to others manufacturers.
The AW 55-50 transmission has a feature that Volvo calls “Neutral Control”. What it “Neutral Control” and what is its function? To tell you the truth, I wasn’t really sure, but below is what I was able to both find and figure out about it.
When coming to a complete stop in drive with your foot on the brake, the TCM waits 2 seconds before disengaging drive or shifting the transmission into neutral. This feature is designed to reduce emissions and to minimize any idle vibrations. When the brake pedal is released, this re-engages drive. This is a very smooth and seamless process that is never felt by the operator.
You can google this https://encrypted.google.com/#q=automatic+transmission+neutral+control