Highway and Transit Projects: Evaluation Guidance Needed for States with National Environmental Policy Act Authority, Report to Congressional Committees [open pdf - 7MB]
From the Highlights: "Since 2005, over 30 provisions have been enacted in law to speed up the delivery of highway and transit projects, mainly by streamlining the NEPA [National Environmental Policy Act] review process. NEPA requires federal agencies to evaluate the potential environmental effects of proposed projects on the human environment. These project delivery provisions included new categorical exclusions to streamline the review process, and a provision allowing DOT [Department of Transportation] to assign federal NEPA approval authority to states. Congress included provisions in statute for GAO [Government Accountability Office] to assess the use of these provisions and whether they have accelerated project delivery."
Government Accountability Office: http://www.gao.gov/