A distributed interlocking device, architecture and process are disclosed, and are based on segregating the vital logic for a signal installation by type of signal equipment. A plurality of intelligent signal devices is disclosed, wherein each intelligent signal device is used to control a basic signal unit. In turn, a signal unit includes a set of signal apparatuses that are geographically and logically interrelated. An intelligent signal device receives data related to the states of other signal devices, determines and controls its own operational states, and communicates its own operational states to other devices.A generic intelligent signal device is also disclosed, and is based on a parameterization approach. The device is then customized to a site specific location by activating the appropriate parameters for that location. Further, a new vital change management process, and a new failure recovery scheme are disclosed.