A megaproject is an extremely large-scale construction and investment project.
According to the Oxford Handbook of Megaproject Management, "Megaprojects are large-scale, complex ventures that typically cost $1 billion or more, take many years to develop and build, involve multiple public and private stakeholders, are transformational, and impact millions of people". However, $1 billion is not a constraint in defining megaprojects; in some contexts a relative approach is needed, such as in developing countries, where a much smaller project could constitute a megaproject. Therefore, a more general definition is "Megaprojects are temporary endeavours characterised by: large investment commitment, vast complexity , and long-lasting impact on the economy, the environment, and society".
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