The cars were accessed by doors which were automatically opened using a pneumatic system (a loud clunk would be heard and the doors would swing open at the press of a control button on the outside of the monorail near the driver door) and manually closed by a Cast Member (who would walk from one end of the train to the other with his hand out, pushing the doors shut as he walked by).
The cars were entered through doors that swung open with a pneumatic mechanism (a loud clunk was audible, and the doors opened with a button press on the outside of the monorail near the driver door) and closed manually by an employee (who would walk along the length of the train, extending his hand to push the doors shut as he passed).