The state Department of Transportation says many city commuter rail trains will be unable to access South Station. The Massachusetts Bay Transportation Authority and commuter rail operator Keolis Commuter Services will have workers at key stations to help guide passengers. A frustrated Gov. Charlie Baker said during his monthly "Ask the Governor" segment on WGBH-FM that his administration has asked Amtrak if the signal would be fixed by the afternoon rush hour and Amtrak could not give a definitive answer.