[liketochill]

Wise moves on the part of the project proponent, had they presented their project with a 17 year construction and 11 billion euro budget it never would have been started.

Humans are optimistic. If we knew in the beginning how long something will actually take we never would start many things.

[rocmcd]

This is the "hiding hand" principle at play.

https://en.wikipedia.org/wiki/Hiding_hand_principle

I highly recommend anyone interested in "megaprojects" to listen to this EconTalk podcast episode with Bent Flyvbjerg:

https://www.econtalk.org/bent-flyvbjerg-on-megaprojects/

Very insightful conversation.