Abstract

A traffic control system for governing from a central office train control equipment such as track switches and track signals which are disposed along a stretch of railroad track. The control system is flexible in that it can operate with either the CTC (unit lever) type of control wherein the operator designates the particular condition or position of track switches and track signals, or in an NX mode wherein the operator merely designates a particular entrance and exit for a particular route. The control system offers still further flexibility in enabling the operator to simply initiate a passing move on a stretch of railroad track which includes a siding. Still further flexibility is built into the control system in that it allows the operator to designate conflicting control requests at the same time. After the particular operator selected control requests have been entered the control system checks the validity of the selected control requests in a predetermined sequence. Those control requests which can be properly executed under the existing traffic conditions are transmitted to the field. Those controls which the control system indicates cannot be validly transmitted at the time of entering are maintained pending and, if conditions in the field change such as to make the previously entered controls valid, then these controls are transmitted for execution in the field.