It sounds like you were getting the results you wanted with the routine you were following before. So, you just need a replacement for the treadmill. If you are going to college they will likely have a gym with a cardio room. Get in early and book your time. If that is not convenient how about getting a bicycle? For personal safely, see if there is a club you can join so you don't end up alone on a bikepath or secluded area of the campus.
Keeping up with the running could also be useful. Again don't ignore your personal safety.
If you are trying to target the appearance of tone in your lower abs and legs then rember that the
body fat issues are
spot reduction issues. We all know the drill in answer to that one. You may or may not get smaller legs. Just stay consistent and you will see results.
Don't forget to change up the routine you do every 4-6 weeks. If you get inot a rut you'll see diminishing returns.
Good luck with your studies and don't fall into the student lifestyle too hard!