Crossrail is the 4th most costly &#x27;megaproject&#x27; involving transport both under construction and 4th including all completed projects. There isn&#x27;t any way to look at it where it isn&#x27;t one of the world&#x27;s largest construction projects unless you start looking at space stations and if cities were &#x27;megaprojects&#x27;<p>[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;List_of_transport_megaprojects" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;List_of_transport_megaprojects</a>