Central Ohio Transit Authority officials and the union representing its bus drivers and mechanics have scheduled contract talks for Sunday to resolve the salary issues that are holding up a new deal. The Transport Workers Union rejected a tentative agreement that included raises and higher worker contributions to pensions. COTA's bus drivers and mechanics could walk off the job Monday without a contract. Columbus safety officials have encouraged those who plan on attending the July 3rd fireworks show downtown to carpool in case of a strike.