C-4 connects Central and West Campuses on weekdays. (Monday through Friday 7:15 a.m. - 5:00 p.m.). Weeknight and weekend service is replaced by the CCX.
Visit this page for details:http://parking.duke.edu/buses_vans/bus_sched/C4_Central_West.php
For general information call the Duke University telephone operator at (919) 684-8111