Yes, COMMUTERS is a Scrabble word!

Letter values in Scrabble US: C 3, O 1, M 3, M 3, U 1, T 1, E 1, R 1, S 1.

Is it a valid word?

COMMUTERS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a passenger train that is ridden primarily by passengers who travel regularly from one place to another
someone who travels regularly from home in a suburb to work in a city

Also: commuter train.