Korean through signs: ad on bus in Seoul promoting clean air

The ad featured here is the one on the bottom (the one on the top is for a university).

The ad says:

제주도처럼
서울의 공기를 맑게
대중교통 이용으로
함께 만들어요!

제주도 - Jeju (the island in the south, known for nature and clean air)
처럼 - like, as
공기 - air. 서울의 공기 - Seoul's air
맑다 - clear. 맑게 - putting 게 here implies a state of becoming, so 서울의 공기를 맑게 means "(making) Seoul's air clean". The sentence is unfinished, but if you were asking someone to make Seoul's air clean you would add a 해주세요 (please do it) on the end, so 서울의 공기를 맑게 해주세요 means "please clean up Seoul's air".

대중교통 - mass transit
이용 - use, usage
으로 - with. Thus 대중교통 이용으로 = using mass transit
함께 - together
만들어요! - make (it)! The verb is 만들다.

All together, the ad means "let's work together with public transportation to make Seoul's air as clean as Jeju's!", in other words "take the bus as much as possible".