A method and an apparatus for a
train control installation are disclosed, and are based on the absolute permissive block concept. The
train control installation employs a plurality of generic absolute block
signal units (ABSU), wherein each
signal unit includes means for detecting the crossing of a
train passed a discrete point, means for exchanging data with adjacent ABSUs, means for generating and communicating a movement authority limit to a train, means for generating and displaying a
signal indication, and means for enforcing a stop aspect. The train control installation can be used in conjunction with a communication based train control (CBTC)
system to provide a
degraded mode of operation without impacting the availability and the reliability of the CBTC
system. Further, the train control installation has a self-healing feature to maintain train service during an ABSU failure.