Megaproject

megaproject: extremely large scale investment project.

Megaprojects include bridges, tunnels, motorways, railways, airports, seaports, power plants, dams, wastewater projects, oil and natural gas extraction projects, public buildings, information technology systems, aerospace projects, and weapons systems.

Defined by the The US Federal Highway Administration as infrastructure projects which cost in excess of US$1 billion, or projects of a significant cost which attract high level public attention or political interest.

Construction feats on same scale as Hoover Dam, Panama Canal etc:

Often there is megaproject pathology, where a government wants to do something for show rather than a requirement. When a group of constructions would have the same affect, and be cheaper. Or the project might be a "convenient" way of removing certain types of people from an area. Such as a ethnic cleansing. A dictator might use it to make a show of force.

Yet often they are the only option with no alternative. What was the alternative to the Suez. And often they are required to raise the moral of a region, or as propaganda.