Precision railroading

Precision railroading or precision scheduled railroading (PSR) is a concept in freight railroad operations pioneered by E. Hunter Harrison in 1993 and has since been adopted by nearly every North American Class I railroad. It shifts the focus from older practices, such as unit trains, hub and spoke operations, and individual car switching at hump yards to emphasizing 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, intermodal trains and general merchandise trains operated separately; under PSR they are combined as needed, typically with distributed power. Inventories of freight cars and locomotives are reduced and fewer workers are employed for a given level of traffic. The result is an often substantial decrease in railroad operating ratios and other financial and operating metrics at the cost of less-reliable service (particularly to smaller customers), long-term capacity issues, and possibly increased derailments and other safety risks associated with longer trains and crew fatigue.^[1]