Canadian National Railroad Practice Exam

The key idea is that trains and engines are identified by the railroad’s initials plus the engine’s number. This combination—often written as a reporting mark (the letters for the railroad) followed by the locomotive’s number—uniquely identifies a specific locomotive within the network. For example, CN 1010 clearly points to a particular CN locomotive, regardless of its other characteristics.

Engine type and horsepower describe what the engine can do, not which engine it is. A train name with a road number isn’t the standard universal identifier for the locomotive across the system. Crew initials and run number relate to the crew or assigned run, not to the locomotive’s official identification.