It depends on the park. All drivers (unless we have a brain fart) have specific routes to each park.
CBR to/from MK uses World Dr to BVD to the main entrance.
CBR to EPCOT gors out the Aux entrance to Victory Way to Osceola Parkway to World Dr to Epcot Ctr Dr. From EPCOT it's Epcot Crt Dr to BVD past the main entrance to CBR to Victory and in the Aux gate.
So you can see, different parks, different routes. Routing in the early morning can change as a dispatch to Magic may be pickup on B side only (Aux gate) for Jamaca, Aruba and Barbados.