These Regulations amend the Railways (Accident Investigation and Reporting) Regulations 2005. They insert a definition of “working days” in regulation 2(1) (an expression used in regulation 4 of those Regulations to describe the time within which accidents or incidents must be reported). They also insert the word “reasonably” before “determine” in regulation 12(4) (providing for the time within which a safety authority may require a person to consider or act upon a recommendation of the Rail Accident Investigation Branch and to provide it with certain information).