What is the abbreviation for the Norristown Line?

The abbreviation for the Norristown Line is "NOR." This choice effectively captures the line's name and provides a clear and straightforward acronym that is easy for both operators and passengers to recognize and remember.

Abbreviations in transit systems are typically chosen to be both concise and relevant to the service's name or route, making "NOR" an ideal fit. The use of the first three letters of "Norristown" aids in quickly identifying the line among others, which is especially useful for operational efficiency and passenger information systems.

The other options do not correspond to the Norristown Line; instead, they might suggest different lines or services within the SEPTA system or could be generic abbreviations that don't pertain to this specific route. Thus, "NOR" stands out as the most accurate and appropriate choice for referencing the Norristown Line.