56within the programme (Figure 1). Within whole-lifecycle costs, maintaining and operating infrastructure can be two to five times the capital cost of construction. So, understanding how information is created and needed across the parts of the lifecycle is also fundamental to ensuring the future railway will be value for money in both the short and the long term.In creating infrastructure, information in Crossrail Limited is only needed for two principal reasons: for legal or regulatory requirements (e.g. health and safety, environmental), and to make decisions either during implementation or operation. The latter requires the sponsor or client to understand the different information needs during design, construction, commissioning, operating and maintenance, so they can be procured appropriately.The term 'building information modelling' (BIM) is relatively new (c. 2011) and is used to describe part of a digital information management environment. Its practice uses new technologies and processes to leverage utility from data and information across the lifecycles of creating and using infrastructure. The characteristics of BIM include the creation of a common data environment (CDE), with explicit digital information and data exchange requirements, together with planned, structured information requirements at each project lifecycle stage.These new technologies and processes are heavily dependent on exploiting technology developments. In the 10 years since Crossrail's parliamentary phase in 2005-2008, the unit cost of processing power has decreased by 50 times, storage costs reduced by 15 times, bandwidth increased by 40 times and the cost of sensors halved. This is having a profound effect on the way Crossrail and other projects can manage and leverage trusted data in creating infrastructure, and then understanding how the infrastructure is behaving in use.
IntroductionThe Crossrail project to deliver the east-west Elizabeth line railway across London, UK, comprises ten new stations, 42 km of tunnels, works to surface railways, and associated depots and maintenance facilities. With a £14·8 billion funding envelope and in construction from 2008 to 2019, the new line will increase central London's rail passenger transport capacity by 10% and secure a £42 billion net benefit to the UK economy in present value terms over a 60-year period.Crossrail Limited was created as a subsidiary of Transport for London (TfL) to deliver the Crossrail programme to the requirements of sponsors TfL and the Department for Transport (Wright et al., 2017). Design and construction of the Elizabeth line is an example of a highly complex programme of projects to manage, as evidenced by the contractual arrangements required to deliver the systems and infrastructure.With 23 framework design contracts and 83 construction and logistics contracts (often with multiple interfaces), the risk of miscommunication, duplication, use of out-of-date documentation and data interface problems was significant. The complexity was caused not just by the scal...