superhighway vs carriageway

superhighway and carriageway both are nouns.

Word	Noun	Adjective	Verb	Adverb
superhighway	Yes	No	No	No
carriageway	Yes	No	No	No

superhighway (noun)	carriageway (noun)
a broad highway designed for high-speed traffic	one of the two sides of a motorway where traffic travels in one direction only usually in two or three lanes
an extensive electronic network (such as the internet) used for the rapid transfer of sound and video and graphics in digital form