Construction work on the programme started in 2009 and tunnelling began in 2012.47 The majority of major construction work is complete and Crossrail Ltd is now transferring assets, such as stations, to Rail for London Infrastructure (RfLi) and London Underground who, along with Network Rail, will maintain and operate different parts of the railway.48 Crossrail Ltd estimates that the central section of the Elizabeth line will be open to passengers between February 2022 and June 2022.49 Our evidence session was in July 2021, some seven months before the earliest opening date.