The provision of $8 billion for intercity passenger rail projects in the 2009 American Recovery and Reinvestment Act (ARRA; P.L. 111-5 ) reinvigorated the development of high speed intercity passenger rail (HSR) transportation in the United States. While Congress has been interested in HSR since the 1960s, the ARRA funding represented an enormous appropriation in historical terms. The $8 billion was included in ARRA largely at the behest of President Obama, and a subsequent announcement in April 2009 made it clear that the development of HSR is a priority of his Administration. Another $2.5 billion was provided for high speed rail and intercity passenger rail projects in the Transportation, Housing, and Urban Development, and Related Agencies (THUD) Appropriations Act, 2010 ( P.L. 111-117 ). Since then, no additional funding has been appropriated for this program. The FY2011 THUD appropriations act ( P.L. 112-10 ) rescinded $400 million from prior year unobligated balances for high speed and intercity passenger rail projects. Other than the rescinded amounts, virtually all of the federal HSR funding made available over the past few years has been obligated and various projects are proceeding. In most places, these projects entail upgrading existing lines owned and operated by freight railroads to allow somewhat faster passenger train speeds than are currently possible. On the Chicago-St. Louis line, for example, funding is being used to increase the maximum speed from 79 miles per hour (mph) to 110 mph. Only the HSR project in California is using federal funds for tracks dedicated to passenger trains, on which speeds could reach 220 mph. Plans for HSR in some states, including Florida, Wisconsin, and Ohio, were shelved by political leaders opposed to the substantial spending such projects entail, particularly for capital and operating costs. Some projects were stopped after federal funds were awarded; these funds were subsequently redirected to HSR projects in other states. Debate on the merits of HSR may continue where projects are ongoing because these projects are often only small steps along the way to providing much faster service in an entire corridor. A key aspect of the debate concerns prospects for the continued development of HSR if no more federal funds are forthcoming. Congress has long been interested in the potential benefits of high speed rail. The first high speed rail act, in 1965, contributed to the establishment of the nation's fastest rail service, the Metroliner, on the Washington, DC, to New York City portion of the Northeast Corridor (NEC), when that line was still under private ownership. In the 1970s, ownership of the NEC was transferred from the bankrupt Penn Central to Amtrak, a government-controlled company. At the same time, Congress initiated the Northeast Corridor Improvement Program, which has funded major infrastructure improvements and, in the late 1990s, purchase of new high speed Acela trains for Amtrak. Congress has also supported research into various high speed rail technologies and studies of potential high speed corridors outside of the NEC where speeds are currently slower (see Table 1 ). The Federal Railroad Administration (FRA) has calculated that Congress provided a total of $4.17 billion to various high speed rail projects between 1990 and 2007, an average of $232 million annually (not adjusted for inflation). Most of that money went to improvements on the NEC. There have also been state and private sector efforts to develop dedicated high speed rail lines without federal support. But it was only in February 2009, when Congress passed the American Recovery and Reinvestment Act (ARRA; P.L. 111-5 ), that the federal government dedicated large sums to a national high speed rail program. ARRA provided $8 billion specifically for intercity passenger rail projects, including high speed rail projects. Intercity passenger rail projects were also eligible uses for the $27 billion provided for highways (at the discretion of individual states) and for the $1.5 billion provided for discretionary grants for surface transportation projects "that will have a significant impact on the Nation, a metropolitan area, or a region." Another $90 million was provided for grants to states for intercity passenger rail projects in the FY2009 appropriations act ( P.L. 111-8 ), following a $30 million appropriation for such purposes in the FY2008 appropriations act ( P.L. 110-161 ). In March 2009, the Obama Administration announced that it would ask Congress to provide $1 billion annually for high speed and intercity passenger rail projects. It has requested that much or more in its annual budget proposals. Congress approved $2.5 billion for high speed rail and intercity passenger rail in FY2010 ( P.L. 111-117 ), but has provided no funding since then. In addition, the FY2011 appropriations act rescinded $400 million from prior year unobligated balances of program funding. There have been several other recent congressional initiatives supporting high speed rail (see Table 2 ). The Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU; P.L. 109-59 ), as amended by the SAFETEA-LU Technical Corrections Act ( P.L. 110-244 ), made $90 million available for maglev projects. In the fall of 2008, Congress passed the Passenger Rail Investment and Improvement Act of 2008 (Division B of P.L. 110-432 ). Among other things, this act created a high speed rail development grant program with a total authorization of $1.5 billion over FY2009-FY2013. The act also authorized additional funding for Amtrak to address some of the backlog of maintenance needed to bring the Northeast Corridor up to a state of good repair. It included a provision directing the U.S. Department of Transportation (DOT) to seek private companies to build and operate one or more high speed lines. In evaluating these efforts, it is important to note that there is no single definition of what constitutes high speed rail. The European Union defines HSR as separate lines built for speeds of 250 kilometers per hour (kph) (155 mph), or existing lines upgraded to speeds of 200 kph (124 mph), or upgraded lines whose speeds are constrained by circumstances such as topography or urban development. The U.S. government also has several definitions of what constitutes high speed rail. FRA has defined high speed rail as service "that is time-competitive with air and/or auto for travel markets in the approximate range of 100 to 500 miles." As FRA notes, this is a market-driven definition which recognizes that, in choosing a transportation mode, travelers are more interested in total trip time than in top speed, and that travelers evaluate transportation modes not in isolation, but by how those modes compare to each other. Congress has, at different times, established high speed rail funding programs using different speed-based definitions and eligibility criteria (see Table 3 ). In its strategic plan for high speed rail, FRA defined three categories of high speed rail corridors. These categories differ in terms of top speeds, track characteristics, and service frequency (see Table 4 ). A map of the corridors defined by FRA appears in Figure 1 . As these various definitions show, discussions of high speed rail in the United States can refer to trains briefly reaching speeds of 90 mph on tracks shared with freight trains or trains traveling over 200 mph for sustained periods on dedicated track, or both. For clarity, in this report the term "higher speed rail" will refer to HSR on shared tracks with speeds up to 150 mph (encompassing both FRA's "Emerging HSR" and "Regional HSR" classifications), and "very high speed rail" will refer to HSR on dedicated tracks with speeds over 150 mph (equivalent to FRA's "Express HSR" classification). In response to the $8 billion that Congress provided for high speed and intercity passenger rail capital grants in ARRA, FRA received 45 applications, representing 24 states, requesting a total of approximately $50 billion. Initial funding awards were announced on January 28, 2010, with the biggest awards going to California ($2.25 billion), Florida ($1.25 billion), Illinois ($1.1 billion), and Wisconsin ($810 million). Applications to FRA for the $2.5 billion appropriated in FY2010 numbered 132 and amounted to $8.8 billion. Awards for these funds were initially announced October 28, 2010. California received another $901 million and Florida another $800 million. Iowa received $230 million and Michigan $161 million in this second round of funding. Newly elected governors in some states, including Florida, Ohio, and Wisconsin, subsequently decided not to pursue the improvements for which their states had sought federal funds. Florida, for example, dropped plans to build a high speed rail line between Orlando and Tampa. As a result, these federal funds were reallocated to other projects. According to DOT, nearly 85% of the funding awarded over the past few years is concentrated in six corridors. Investments in five of the corridors are aimed at upgrading existing lines. These five corridors are Seattle-Portland; Chicago-St. Louis; Chicago-Detroit; the Northeast Corridor (NEC); and Charlotte-Washington, DC. In the sixth corridor, Los Angeles-San Francisco, the plans are to build a new very high speed rail line that may allow trains to reach speeds of up to 220 mph. The remaining 15% or so of funding is going toward a multitude of smaller projects throughout the country, including planning studies and station and track improvements. Table 5 shows obligated funding by state. Some corridors have also received discretionary grants from the Transportation Investment Generating Economic Recovery (TIGER) program. A wide range of road, rail, transit, port, and intermodal projects are eligible for TIGER funding.