railroad man vs railway man

railroad man and railway man both are nouns.

Word	Noun	Adjective	Verb	Adverb
railroad man	Yes	No	No	No
railway man	Yes	No	No	No

As nouns, railroad man and railway man are synonyms defined as:

Other synonyms of railroad man include railroader, railwayman, trainman.

railroad man (noun)	railway man (noun)
an employee of a railroad	an employee of a railroad