I don't go to OHSU but have visited portland and took the tram up to the hospital because it's an awesome view. I don't know where you're staying while you're there but the tram up to the hospital may be your best bet if you can walk to it or park nearby in the morning and take it up. There always seemed to be residents on it as a way of getting to and from the hospital. It should be free if you're working up there it's not incredibly slow or anything either. Hope that makes some sense or helps at all.