That would definitely be nice, but the biggest problems with ingress and egress are on the property at COTA itself. And a rail line, as someone mentioned on the Autosport board the other day, will never make any sense as long as it would be just COTA at the end of the line. There are only a few days out of the year that COTA would actually need it.
The biggest help imho would be COTA getting its shit together on race days, not skimping on buses, on-site personnel and traffic control, cooperating with the neighbors who sell parking, like Daytona and IMS do, instead of trying to shut them down, etc. Hell, Daytona arranges free parking right across the road from the NASCAR T4 entrance for people who don't want to pay for on-site parking (which is typically not crazy expensive to begin with). We parked there last year, at the mall. This year my kid parked there again and slept in his car instead of going to a hotel. He said the track had also provided portapotties in the lot for people who might be staying in their cars. Bobby would rather set himself on fire than do anything like that.
Oh, and the first event was the 2012 USGP. MotoGP was next in April 2013, and then V8SC in May. Here's some typical COTA fuckshittery though: COTA has a page with a history of the events they've held. On it, they list V8SC as a support race of the Pirelli World Challenge weekend. LMAO WTF? It was the other way around. It was all billed as a V8SC race weekend, with PWC as a support series. Even wikipedia shows PWC as a support race for V8SC that weekend. PWC has its own weekends here now. I guess this is COTA's lame attempt to make a current race weekend seem like a bigger deal than it actually is, and maybe also to diminish V8SC after they pulled out of COTA.
https://circuitoftheamericas.com/timeline/#2012-2