that's a really sweet and unique setup... just that i see some problems.
- 45min too short (and expensive) to really get in to more than one or two machines. also may be too short to get used to the track's curves.
- if that many people are allocated per trip, you may have little or no choice what to play!
- the trip itself sounds very pleasant and relaxing; not sure i'd really want to spend it playing PB.
i think it might be more practical just to make the machines pay-to-play and opening them to all and sundry. *shrug*