Hey, amstaffmom, thanks! That's exactly what we ended up doing. There's some very pretty backroads near where we live, so we went for about an hour. Then the next day, I went by myself (stopping every hour to call and tell him I was still alive) on a mapped out route. It was liberating! Tomorrow, I go on my local, in town roads (to the gym and library). It was just finally getting sick of the parking lot and saying "I'm as ready as this darn parking lot is going to make me!"
We are still going to the parking lot for skills practice once a week. Now, rather than him teaching me, it is both of us practicing our swerving and hard stops, etc. (He even bought cones

)
Anyway, this site, and others I've found, have made it much more possible for me to keep growing with this- just by lurking.