motorway vs thruway

motorway and thruway both are nouns.

Word	Noun	Adjective	Verb	Adverb
motorway	Yes	No	No	No
thruway	Yes	No	No	No

As nouns, motorway and thruway are synonyms defined as:

Other synonyms of motorway include expressway, freeway, pike, state highway, superhighway, throughway.

motorway (noun)	thruway (noun)
a broad highway designed for high-speed traffic	a broad highway designed for high-speed traffic