ring road vs beltway

ring road and beltway both are nouns.

Word	Noun	Adjective	Verb	Adverb
ring road	Yes	No	No	No
beltway	Yes	No	No	No

As nouns, ring road and beltway are synonyms defined as:

ring road and beltway: a highway that encircles an urban area so that traffic does not have to pass through the center

Other synonyms of ring road include bypass, ringway.

ring road (noun)	beltway (noun)
a highway that encircles an urban area so that traffic does not have to pass through the center	a highway that encircles an urban area so that traffic does not have to pass through the center