I will be taking the commuter rail to my classes in Cambridge starting in September (a different line than Jolt). There's no parking at all in Porter Square and the university highly discourages people from taking their cars. However, there's no student discount for the commuter rail, only for trolleys, buses, commuter boats. I felt a little weird about asking about the student pass at my age, but, I figured what the heck? The train home leaves at the same time as my last class ends, so I am going to try to get permission to leave 5 minutes early (the station is next door to the building where I will be). Otherwise, I will be hanging around an extra hour and 15 minutes, since it becomes off peak time, after 6:30PM.
The good thing is, the train station is 5 miles from my house and the local grocery store lets people park in their lot; otherwise, there's like ten spaces by the station. Parking at the local commuter rail stations is a real problem in the suburbs here. There just isn't enough space.