Dan Simmons has left his post at TCD to return to the Department of Public Transportation, it’s understood.He has swapped positions with Jonelle Christopher, who becomes acting director of TCD, according to sources.Staff reported Mr Simmons said his farewells at TCD yesterday; in the afternoon it’s understood he was already back at the DPT.Government would neither confirm or deny the information yesterday, while Mr Simmons did not respond to messages.Ms Christopher was formerly assistant director of DPT, before being promoted to acting director when Mr Simmons left for TCD less than a year ago.