20 South Campus Loop operates every 15-20 minutes Monday through Friday from 4 pm to midnight during Purdue’s fall and spring semesters when class is in session. 15 minute express service between Lynn Hall and Discovery Park Lot is provided from 4 pm to 6 pm. 20 minute service is provided from 6 pm to midnight from Krannert and Lynn Hall to Discovery Park Lot and the Purdue Airport. This route serves the southern part of campus along Harrison Street. Destinations include Lynn Hall, Discovery Park Lot, Purdue Village, Purdue Airport/NISW, Krannert, and Lyles-Porter Hall.