guideline vs road map

guideline and road map both are nouns.

Word	Noun	Adjective	Verb	Adverb
guideline	Yes	No	No	No
road map	Yes	No	No	No

As nouns, guideline and road map are synonyms defined as:

guideline and road map: a detailed plan or explanation to guide you in setting standards or determining a course of action

guideline (noun)	road map (noun)
a rule or principle that provides guidance to appropriate behavior	a map showing roads (for automobile travel)
a detailed plan or explanation to guide you in setting standards or determining a course of action	a detailed plan or explanation to guide you in setting standards or determining a course of action
a light line that is used in lettering to help align the letters