A pedestrian passes a locked rail station in west Philadelphia Tuesday. Commuters scrambled Tuesday to find alternate ways to travel as transit workers in Philadelphia hit the picket lines after the city’s main transit agency and a union representing about 4,700 workers failed to reach a contract agreement. The union went on strike at 12:01 a.m. Tuesday, shutting down Southeastern Pennsylvania Transportation Authority buses, trolleys and subways that provide about 900,000 rides a day.