It shifts the focus from older practices, such as unit trains, hub and spoke operations and individual car switching at hump yards, to emphasize point-to-point freight car movements on simplified routing networks.￼￼ Under PSR, freight trains operate on fixed schedules, much like passenger trains, instead of being dispatched whenever a sufficient number of loaded cars are available.￼ In the past, container trains and general merchandise trains operated separately; under PSR they are combined as needed.