No, my SA is still very much present when I am in a different town/city.
Yet if I am in a city where I don't know anyone I feel I can do things that I cannot do in my home city, such as go in to clothes shops. So I would say my SA is reduced when I am in a different town or city, but nowhere near gone. Not even close.
Usually driving only makes my SA worse if I am with another person on the trip. If the person can close his or her mouth for one second and constantly blabbing on and on I get pretty annoyed. If I am by myself however I can cope pretty easily. Traffic sometimes annoys me when idiots cut me off and then I think other people are nosy when they get right beside me and coast along with me as if they are staring at me. That really peeves me.
Then when I am in a new city I don't know where I can escape so it becomes pretty frustrating and I can't wait until I get back to my "home cave."
Nope...Not at all. I went on a cruise once thinking I could be as much of myself as I wanted to be since none of these people were ever going to see me again but it didn't work out that way. My SA was more or less exactly the same.
I find mine is much less when i go to another country. I don't know the language anyway, so it's like the pressure is off - I *know* for sure that no one expects anything of me, I am just another tourist. And I feel no need or pressure to get to know other tourists. My mind is on what I want to see while I'm there, and my husband is with me, and we have a blast.
In fact, I spoke more french to a starbucks clerk once when I was in Paris than I usually speak to the clerks where I actually live (took 3 years french in high school, still remember a little). Of course, then he started speaking to me like I was a native, and I had to admit my ignorance. I think he appreciated the effort though. At least, it's nice to think so.
I've experienced this moving to a different place. It definitely doesn't almost disappear but it lessens. No idea why, maybe because no one expects anything of you (no one knows you as the shy, quiet person)