No time outside on the tour (unless it's a nice day). The campus is connected by tunnels and we try to keep you inside the whole time.
The one caveat is that you might have an interview in a building across the parking lot or off site (if you said you had transport). The ones across the parking lot are connected by tunnels but I've been here two years and I still haven't figured out how to get to them by the tunnels. I'd suggest a quick dash across the lot rather than risking getting lost.
Good luck.