ATLANTA — Voters could decide on their November ballots whether to expand the Chatham Area Transit, if the local legislative delegation agrees on the mechanics. A lobbyist for the CAT board briefed the delegation this morning on a plan for a countywide vote. Representatives from each new city served would be added to the board, along with an additional countywide community appointee. Property taxes would rise along the new routes only. Mike Vaquer, the board’s lobbyist, told the delegation that it needs to pass two bills, one for the referendum and one to expand the board.