The moveable rails (points) at the entry of a turnout that direct a train onto either the straight or diverging track. Switches are operated manually by a switchman or remotely by a signal system. Power switches in yards and at controlled locations are operated electronically from a dispatching center.
A track assembly consisting of a switch, frog, and closure rails that allows a train to move from one track to another. Turnouts are defined by their angle, expressed as a number (e.g., No. 10 or No. 20), with higher numbers indicating a more gradual diverging angle. They are a critical infrastructure component at every junction, siding, and yard entry.
A wayside device that conveys authority and speed information to train crews by displaying light aspects or physical positions. Signals are the fundamental mechanism for maintaining safe train separation in a signaled territory. Signal aspects are governed by rulebooks that define what each combination of lights means.
A large rail facility where cars from inbound trains are sorted and grouped by destination to build outbound trains. Cars may be sorted using hump switching, flat switching, or a combination of both. Classification yards are the central nodes of the carload network.
A safety system mandated by Congress after the 2008 Chatsworth collision that automatically enforces speed limits, prevents train-to-train collisions, and enforces temporary speed restrictions, overriding human error. PTC uses GPS, wireless communications, and digital track maps to monitor and control train movements in real time. All Class I railroads completed PTC implementation by the 2020 deadline.