Basics
Basics of North American Signaling and Safety principles
Basic principles of Automatic Block Signaling, Interlocking, Traffic Control Systems and Centralized Traffic Control
Track Occupancy Control Systems
Track Warrant Control (TWC)
Direct Traffic Control (DTC)
Automatic Block Signaling systems
Southern Pacific single track Automatic Block Signaling
Simulator for SP-style ABS on the Central Oregon & Pacific - added December 22, 2011
Absolute Permissive Block signaling
AT&SF double track Automatic Block Signaling
AT&SF "Flat Pair" single track Automatic Block Signalling
Centralized Traffic Control systems
Pittsburgh & West Virginia "Poor Man's CTC" - new May 20, 2014
Signal Aspects and Indications
Atchison, Topeka and Santa Fe, 1995
Bessemer & Lake Erie Railroad, 1957
Kansas City Southern, 1998
Pittsburgh & West Virginia, 1953 - added February 20, 2013
Southern Pacific, 1996
Union Pacific, 1988
Text, Images except for wallpaper, HTML: Carsten S. Lundsten.
Wallpaper photo: Kindly by Eric Schmelz, modified by Carsten S.
Lundsten