Complex sentence: The Director of Passenger Rail Franchising was abolished and replaced in 2001 by the Strategic Rail Authority and then, when the SRA was abolished in 2006, the franchising functions were taken over by the Secretary of State for Transport.
Split into simpler sentences: The Director of Passenger Rail Franchising was replaced in 2001 by the Strategic Rail Authority. When the SRA was abolished in 2006 franchising were taken over by the Secretary of State for Transport.