thruway vs state highway

thruway and state highway both are nouns.

Word	Noun	Adjective	Verb	Adverb
thruway	Yes	No	No	No
state highway	Yes	No	No	No

As nouns, thruway and state highway are synonyms defined as:

thruway and state highway: a broad highway designed for high-speed traffic

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

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