People tend to forget, large projects, take a lot of time to design, prepare to be constructed and getting all the supplies needed to do the project. One of my favorite stories is the story of the Kinzua Bridge. Every one rave about the fact in the 1890s when it was rebuilt that it took the railroad only 90 days to do the reconstruction (The Reconstruction was the replacing of the origin Iron beams with Steel beams so heavier trains could go over it).
While Kinzua bridge was rebuilt in only 90 days, it had been a ten year project. The Railroad wanted the Bridge replaced, but out of service the least amount of time. Thus the extensive planning the preparation before the reconstruction ever began. All the planning was to get the project done in three months (Yes, ten years of planning to do three months of work, please note the Kinzua Bridge fell in 2006 do to being hit by a tornado. The bridge could have withstood the tornado in 2006, even in its rusty condition of that time had the railroad, during the reconstruction, used new bases and connections to the bases instead of using the existing iron connections to the existing bases. It was those iron connections that gave way in 2006, causing the bridge to Collapse).
More on the Kinzua Bridge:
http://en.wikipedia.org/wiki/Kinzua_BridgeJust pointing out that a lot of what we do before a project is started, was done in the past. We hear of the short construction time periods because all that is counted is the actual construction period NOT the planning before hand. The Hoover dam had been proposed years before, but not built till the Great Depression for President Hoover had the view that large projects should NOT be built during time of prosperity for such project over heated the economy. Instead such projects should wait for a depression, when such excess government spending is needed to kick start the economy. Thus the Hoover dam had been planned for at least a decade before it was even started. The Government had done the equivalent of environmental studies and everything we do today (Through with a lot less knowledge then we have today).
Just a comment that what is being done today, is about the same as what was done then, once you look into the details. The modern view that excessive regulations slows down such projects is a fallacy pushed by people who want to cut out much of the needed input to a successful implementation (The problem with the Iron connections that lead to the collapse of the Kinzua Bridge is a good example of the lack of such regulations).
Large projects need the input from most of the people affected by such projects and getting most people to support something takes a good deal of work. The regulations tend to make it easier to get people to accept such large projects so have massive support from builders of such projects. In many ways such regulations speed up such projects by eliminating most of the opposition to such projects by showing people that someone is watching out for them. Thus most regulations is supported by engineers and other builders of such projects, the attack on such regulations are generally by people who want to build something as cheaply as possible and who cares the risks to other people.