Attempt to arrive 30mins earlier. This way if you run late, you'll still get there about 15mins earlier. Worse case scenario, your there 30mins early andnow you have 15mins to blow macing to random females at your future place of employment.
Had a med school interview that i arrived an hour 30 minutes for because my student host needed to be in the school early. It ended up being a good thing, Igot to build a rapport with everyone in the admission's office including the dean.