Collision1

An impact between on-track equipment consists while both are on rails and where one of the consists is operating under train movement rules or is subject to the protection afforded to trains. This includes instances where a portion of a consist occupying a siding is fouling the main line and is struck by an approaching train. It does not include impacts occurring while switching within yards, as in making up or breaking up trains, shifting or setting out cars, etc. (FRA2)