The nation's network of highways plays a vital role in the U.S. economy; private commercial activity and people's daily lives depend on that transportation infrastructure. In 2007, the public sector spent $146 billion to build, operate, and maintain highways in the United States. About three-quarters of that total was provided by state and local governments. One-quarter was provided by the federal government, primarily through the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU). The initial authorization for that law has expired; as the Congress considers the future role of the federal government in providing highway infrastructure, it faces three important questions: how to structure decisionmaking about highway projects, how much money to spend on highways, and how to pay for that spending.