Programme Status Breakdown
Delay Distribution — Top 12 Schemes (Weeks)
Announced vs. Current Cost — All Schemes (£m)
Cost Escalation Forecast to 2032 — Active Schemes
Crossrail / Elizabeth Line — World-Class, World-Cost
Announced in 2007 at £14.8bn. Final cost £18.9bn — a 28% overrun. Target opening December 2018; actual opening December 2022 — four years late. The longest delay in UK railway history at the time. Yet it delivered: the Elizabeth line now carries 700,000 passengers a day. World-class projects at world-class cost.
Hammersmith Bridge — +530% and Still Not Open
The Victorian suspension bridge was closed to motor traffic in April 2019. Repair costs announced at £46m. Current estimate: £290m — a 530% overrun. Responsibility disputes between LBHF, TfL, and central government paralysed work for years. Pedestrians and cyclists regained access in 2021 but full vehicle reopening is not expected until 2027 at the earliest.
Four Lines Modernisation — Announced 2011, Done by 2031?
Upgrading Jubilee, Northern, Hammersmith & City and Waterloo & City lines — announced 2011 at £6.5bn. Now £9.5bn (+46%). Originally due 2022, revised to 2031+. Thales signalling failures, COVID, and funding squeezes have compounded delays. A 520-week slip on one of London's most critical rail reliability programmes.
Emergency Services Network — A Decade of Failure
The ESN was meant to replace Airwave for all UK blue-light services by 2020 at £9.2bn. Now £11bn+ and not expected until 2030+. Awarded to EE/BT. The Home Office has paid hundreds of millions in Airwave extension fees while ESN remains undelivered. A textbook case of digital megaproject failure impacting London and the UK.
Old Oak Common — £3.1bn Extra and Counting
The HS2/Elizabeth Line interchange station at Old Oak Common was announced at £1.5bn in 2014. Cost has risen to £4.5bn — a 200% increase — and the completion date has slipped from 2033 to 2035+. The station will serve as HS2's London terminus until Euston is resolved. With Euston itself paused, Old Oak Common is bearing the entire weight of London's HS2 strategy.
What London Got Right: Tideway and Northern Line Extension
Tideway Tunnel (the £4.5bn Thames Super Sewer) completed 2025 — one year late but only 10% over budget relative to scale. The Northern Line Extension to Battersea opened 2021 at £1.29bn, broadly on budget with only a 26-week slip. These show London can deliver when governance is clear, funding is ring-fenced, and project ownership is unambiguous.
| Scheme | Status | Announced | Current Est. | Variance | Delay | Detail |
|---|
Methodology & Sources
CPD Index (0–100, higher = worse): CPD-C (Cost Performance) measures the severity of cost overruns across the portfolio — a score of 0 indicates no overruns; 100 indicates catastrophic and universal cost failure. CPD-D (Delivery Performance) measures the severity and prevalence of schedule delays. The combined CPD score is the unweighted average. London scores CPD-C: 69, CPD-D: 72, Combined: 70 — reflecting a portfolio where the majority of schemes are over budget or significantly delayed.
Clock: The live clock shows the cumulative active cost overrun on schemes with confirmed cost increases, compounding at a blended BCIS inflation rate of 4.1% per annum (reflecting London's higher construction cost inflation). Clock base: £14.447bn active overrun. Epoch: 05 May 2026 00:00 BST. Rate: £18.32 per second. Completed schemes at final outturn are excluded from the clock base.
Cost data: Announced costs taken from original DfT, TfL, GLA, HS2 Ltd, and Home Office press releases, business cases, and parliamentary statements. Current estimated costs drawn from NAO reports, TfL Board papers, HS2 Ltd annual reports, Hansard, and GLA oversight committee publications.
Delay data: Weeks of delay calculated from original target completion date versus revised target, actual completion date, or today's date (where no revised target exists). Schemes with no formal completion date ever set are classified as Paused or TBC.
Primary sources: National Audit Office (NAO) · Transport for London (TfL) · Greater London Authority (GLA) · HS2 Ltd · House of Commons Transport Select Committee
CPD Index — cost cap: The cost overrun % contribution to CPD-C is capped at 50 points — schemes with overruns above 100% score the maximum on this component. This prevents extreme outliers (e.g. Hammersmith Bridge at +530%) from distorting the index beyond its intended range.
Disclaimer: This tracker is an independent professional assessment prepared by QuintinQS. It is not affiliated with Transport for London, the GLA, HS2 Ltd, or any government body. All figures are drawn from publicly available sources and are correct to the best of the authors' knowledge as of the date shown. Cost projections are indicative only.
CPD — about this acronym: CPD stands for Continued Prolonged Delays — a deliberate reference to Northern Ireland's Central Procurement Directorate, rebranded as Construction, Procurement, Delivery — the NI Executive body whose mandate is to ensure public infrastructure is built on time and on budget. The name is intentional.