The train dispatcher must consider the tonnage and power of each train and how these factors affect acceleration, speed and braking, in which sidings the trains fit, the weather and the characteristic performance of each individual train crew. In addition, train dispatchers must consider when stopping trains to meet opposing trains, to be passed by faster trains or for track maintenance work, the locations of public highway crossings at grade and whether it is practical or even possible to cut the crossings or if the train must be held at some other location. The speeds of the different types of trains on a dispatcher’s territory are radically disparate. Passenger trains will typically operate at 75 to 80 MPH, merchandise freight trains at 55 to 70 MPH and coal or grain trains at 30 to 45 MPH. Actual average speeds of several different engineers may vary by a range of 10 mph. Actual speeds achievable by individual combinations of locomotives and cars may vary more radically than that. A strategic or tactical error in handling a slow moving train or allowing track maintenance work can result in an extensive delay to a passenger train several hours later. The dispatcher employs several means for the strategic planning process, the most important of which are: schedules published in the timetable; schedules published by the Chief Dispatcher and/or by dispatchers on adjoining districts, known as lineups, indicating what traffic including extra or unscheduled traffic will operate; information from direct conversation with dispatchers on adjoining territory; information from traffic-and-transportation oriented (as opposed to the operation oriented systems sometimes furnished for use by train dispatchers) data processing systems; information from direct conversation with yard personnel that make up trains from individual cars and direct conversation with or messages from the maintenance of way forces about scheduled track maintenance work. Train dispatchers are also responsible for instructing appropriate trains to pick up cars which are ready to move at stations between terminals at which trains are made up and part of the strategic planning process involves direct conversation with or messages from personnel handling movement of cars to and from stations between major terminals. Trains of the proper destination and type of traffic which have the capacity for additional cars must then be identified and instructed to stop and pick up the cars. Dispatchers must also keep dispatchers on connecting districts and personnel at stations and terminals informed of the expected arrival of the trains that they are handling so that these others may likewise do their planning.