My son goes to a cross-town affiliate in a large metropolitan area. There are quite a few Mids from his school, so that helps with the car-pooling. Many of the upperclassmen have cars and the seniors have class on the same day as the freshmen, so first semester the seniors each took a few freshmen in their cars. The freshmen chipped in a few dollars each week for gas and maintenance. But the senior he was riding with wasn't available second semester, so my son decided to take his car back with him after the holidays. He's had to learn a lot about driving in a city, maintenance, etc. and it's been a real growth experience for him. But he likes being able to help others get where they need to be, and it helps him get around to get haircuts and dry-cleaning, etc. He also ended up driving to another city for one of the Nuke Club events.
I think one of the biggest challenges was how to get to class on the morning of the first day of school. He and several others took public transportation. They sometimes take public transportation to events also but it's not easy because the stops are far away from the dorms at his school and the NROTC building at the host school. Thankfully, the Mids at his school do PT together so they don't have to go twice a day, they mainly go to the host campus for class and drill.
Also, the cadre told us at Orientation that they don't worry about the transportation for classes and drill because the student leadership takes it on themselves to work it out. And I'd have to say they have done a good job of it.
Oh, one other thing...parking is problematic at both schools, expensive, hard to find, etc. And if a student is one of very few at a cross-town affiliate, all this is probably much more difficult.