Crossrail (Elizabeth Line): The 4-Year Delay
Crossrail was due to open in December 2018 at a cost of 14.8bn GBP. It opened in May 2022 at a cost of 18.8bn GBP. The NAO published two scathing reviews (2019 and 2022) identifying signalling and systems integration as the central failure.
18.8B GBP
final cost
3.5 years
behind schedule
+27%
over original budget (real)
What went wrong, per the NAO
The 2019 NAO report identified three structural failures:
- Signalling integration was scheduled in parallel with civil works finalisation. The three signalling systems (Network Rail mainline, Crossrail central tunnel, and Heathrow approach) had to be integrated by 2018. They could not be, because the central tunnel civils were not complete in time.
- The single-systems-integrator model was abandoned mid-project. Crossrail Ltd took on the role itself, without the capability to do so. The 2022 NAO report singled this out as the "most significant strategic error".
- Cost-to-complete forecasting was missing for the systems work. Civils were tracked in detail, but systems integration cost had no equivalent earned-value baseline. Slippage was invisible to the board until it had compounded into a year-long delay.