Freight vs. passengers?

The demands of customers for punctual freight service are ever-increasing. More and more, industry organizes its materials supply on a just-in-time basis.

For example, as of 2000, SBB was handling a train of auto parts that moved from France directly to an assembly line in an automobile plant in Hungary. Another time-sensitive type of traffic is the "rolling motorway", in which tractor-trailer trucks are loaded on flatcars for movement across the Alps.

Random variables

From the viewpoint of the dispatcher, the difficulty with freight trains is that many factors - most of which are beyond the dispatcher's control - may delay them, including processing at the origin customer, safety inspections before departure, and customs checks at the border.

Also, both the composition and motive power of a scheduled freight train may vary widely from day to day. The train's consist affects both its accelleration and its cruising speed, especially on long uphill grades. In some cases, the dispatcher or local operator may ask the train driver via telephone about the makeup of today's train and his forecast of how fast the train will get over the line.

Given the many factors that can affect it, and its generally lower priority compared to the many passenger trains, planning the movement of a freight train more than about 15 minutes in advance is tricky.

Priorities

Although passenger trains generally receive priority over freight trains, a dispatcher will sometimes hold a lightly-loaded local passenger train and let a postal or other high-priority freight train go first. In other situations, however, particularly during rush hour, a freight train that is only 3 minutes late may have to wait a half hour for six passenger trains.

Running ahead of schedule

Another way to avoid conflicts is to run a freight train ahead of schedule if circumstances permit. This is almost impossible with passenger trains, with their scheduled station stops.