From the summary:
Surface transportation programs need to be reexamined in the context of the nation’s current unsustainable fiscal path. Surface transportation programs are particularly ready for review as the Highway Trust Fund faces a fiscal imbalance at a time when both congestion and travel demand are growing. As you requested, this report (1) provides an overview of the federal role in surface transportation and the goals and structures of federal programs, (2) summarizes GAO’s conclusions about the structure and performance of these programs, and (3) provides principles to assess options for focusing future surface transportation programs. GAO’s study is based on prior GAO reports, stakeholder reports and interviews, Department of Transportation documents, and the views of transportation experts.