In an academic paper, University College London and University of Sussex academics have identified 18 reasons why megaprojects such as Crossrail and HS2 often fail and also proposed 54 preventative solutions.

What Are the Causes and Cures of Poor Megaproject Performance? A Systematic Literature Review and Research Agenda
Authors: Juliano Denicol, Andrew Davies, Ilias Krystallis

First Published February 13, 2020 Research Article

Abstract

This systematic literature review explores the megaproject management literature and contributes by improving our understanding of the causes and cures of poor megaproject performance. The review analyzes 6,007 titles and abstracts and 86 full papers, identifying a total of 18 causes and 54 cures to address poor megaproject performance. We suggest five avenues for future research that should consider examining megaprojects as large-scale, inter-organizational production systems: (1) designing the system architecture; (2) bridging the gap with manufacturing; (3) building and leading collaborations; (4) engaging institutions and communities; and (5) decomposing and integrating the supply chain.

You can read the paper here: https://journals.sagepub.com/doi/10.1177/8756972819896113

and download from here as a PDF document: https://journals.sagepub.com/doi/pdf/10.1177/8756972819896113