island vs safety zone

island and safety zone both are nouns.

Word	Noun	Adjective	Verb	Adverb
island	Yes	No	No	No
safety zone	Yes	No	No	No

As nouns, safety zone is a hyponym of island; that is, safety zone is a word with a more specific, narrower meaning than island:

island: a zone or area resembling an island
safety zone: a curbed area in a roadway from which traffic is excluded; provides safe area for pedestrians

Other hyponyms of island include kitchen island, safety island, safety isle, traffic island.

island (noun)	safety zone (noun)
a zone or area resembling an island	a curbed area in a roadway from which traffic is excluded; provides safe area for pedestrians
a land mass (smaller than a continent) that is surrounded by water