I was allowed to play outside on my own starting at about age 7. I started walking to school alone after we moved to Houston, when I was nine and in fourth grade. Around the same time, I also started walking to the park by myself, and I remember very clearly being allowed to walk to the Stop 'n Go down the street for the first time. (I bought a candy bar and a Richie Rich comic book. Good times.)
2. How old were you when you started taking public transit on your own? What were the circumstances?
I started taking the public bus to school at the beginning of ninth grade, so I would have been 13, almost 14. I went to school in another city, and it was quite a long trip -- 45 minutes on two buses.
3. How old were you when you first took a long-distance trip (unaccompanied on the bus, train, or plane, even if you were met at your destination) on your own? What were the circumstances?
I don't think I ever did this as a child. I do remember that when we lived in Houston, my best friend from Louisiana, who would have been about 11 at the time, flew by herself to spend a week visiting me.
4. This set of questions was inspired by a news story about a woman leaving her nine-year-old in downtown Manhattan to find his own way home on transit and the controversy it caused (http://news.aol.com/newsbloggers/2008/0
I think a lot of the people who flipped out about this are from the suburbs. Nine is too young, IMHO, but most of the people I've met who grew up in NYC started using public transit independently at a pretty early age. Incidentally, this is also really common in large European cities -- I used to know someone from Paris, and she said that she and all her classmates were taking the metro to school alone by the time they were 11 or 12. (Now, whether I would let G do this is another story -- see the next question.)
5. At what age would or did you let your kids (hypothetical kids, if you don't have them) do those things where you live now?
G is 10 -- close to 10 1/2, actually -- and she isn't allowed to play outside or go anywhere by herself. If we lived in the neighborhood immediately surrounding her school, where there isn't a lot of traffic and most of the people know each other, I would most likely let her walk to school next year (fifth grade) if she walked with a friend. But, we live on a busy street and don't know our neighbors, so she's not going to be walking anywhere without me in the near future. Maybe when she starts junior high.
As for the other situations, I wouldn't allow her to take public transit alone until high school, and probably not even then. Our bus system is awful and it's easy to miss a connection and get stranded somewhere, plus I have not-so-fond memories of being harassed by men, both in cars and on foot, while waiting at the bus stop. On the other hand, I probably would let her fly alone to visit relatives at 13 or so, assuming someone I trusted was meeting her at the other end.