Exit Signal Types Exit Signals may be divided into two physical and two logical types. Logically Exit Signals are divided into advance signaling Exit Signals and non advance signaling Exit Signals. Non advance signaling Exit Signals are found where the next Main Signal is preceeded by a Distant Signal. Non advance signaling Exit Signals are always the 2-lamp type. Advance signaling Exit Signals on main lines are always the 3-lamp type.
Some installations vary from the rule.
Proceed at prescribed speed. In the example below, Exit Signals are placed at the end of the platform tracks. This configuration is only used on minor stations with 2-4 platform tracks, most of them on single track lines. The Exit Signal acts both as the signal protecting the line and as the signal informing which train is to depart. The latter task is then carried out by a signal placed at the end of the platform track, while the Exit Signal is placed near the Station Limits, usually with the Switch Limit Board on the same mast.