Public transit in Troy isn't anything to write home about, but it meets most students' needs. You can get basically anywhere you need to go, though it may take longer than you want. The CDTA buses have routes both through RPI campus and Troy, all of which are free with a student ID-and the bus drivers usually don't mind if you and your 10 friends hop on the bus a little drunk for a ride back to campus. For the most part, however, if you want to get around town, it's usually just as fast to walk. The bus is a nice option to have in the cold winter months, but it's important to allow extra time.
For getting out of town, the bus can take you to the airport or train station. In terms of more practical needs, routes head to the local Price Chopper and Wal-Mart-again, all free of charge. Of course it's not as fast as a car, but it's free and beats walking across town with your groceries in hand. It's rumored that RPI plans to expand the off-campus bus routes, allowing students who live farther off campus easier access; while this may happen in the coming years, right now it's just as easy to drive if you have a place too far away.