Virginia Postrel reports on Bent Flyvbjerg’s studies into the costs of public infrastructure projects:
On average, urban and intercity rail projects run over budget by 45 percent, roads by 20 percent, and bridges and tunnels by 34 percent.
And the averages tell only part of the story. Rail projects are especially prone to cost underestimation. Seventy-five percent run at least 24 percent over projections, while 25 percent go over budget by at least 60 percent, Flyvbjerg finds.
By comparison, 75 percent of roads exceed cost estimates by at least 5 percent, and 25 percent do so by at least 32 percent.
Promoters of rail and toll-road projects also tend to substantially overstate future use, making those projects look more appealing to whoever is footing the bill. Rail projects attract only about half the expected passengers, on average, while in new research still in progress, Flyvbjerg finds that toll roads (including road bridges and tunnels) fall 20 percent short.
This doesn’t bode well for Crossrail. I’m also wondering how the M6 toll road is working out. It seems like a fantastic road to me, but is it making enough money?