In 2003, NCHRP Project 19-05, “Assessing and Mitigating Future Impacts to the Federal Highway Trust Fund Such As Alternative Fuel Consumption,” produced a report (available for download on that project’s web page) that explored scenarios of future fuel use and corresponding consequences for fuel-tax revenues. The analysis concluded that, while there are serious threats to the continued usefulness and stability of motor fuel taxes as the principal funding source for the nation’s surface transportation system, those threats were neither unlimited in the long term nor likely to have major impacts over the effective period of then-current federal transportation program authorization.
That report was based on sound analysis and its conclusions were reasonable for the time, but today conditions are dramatically different. A new period for Congressional authorization of transportation programs is at hand. Fuel prices are at high levels and generating public controversy. Congress has enacted significant changes in Corporate Average Fuel Economy (CAFÉ) standards, the first such change since 1975, and may make further changes in the future. Increasing worldwide emphasis on coping with greenhouse gases and their impacts on global climate change amplifies pressures to further reduce our reliance on traditional motor fuels; these pressures could motivate other Congressional action to mandate changes in fuels and vehicles. It is plausible that forecasts presented as the “base case” expectations in the 2003 report could occur much faster than was anticipated or that reasonable analysis would conclude that substantially different trajectories of fuel usage will be followed.
The state DOTs and AASHTO are developing policies and plans to ensure the long-term sustainability of our transportation system. To be effective, these policies and plans must be based on current data and assessments regarding what fuel efficiencies may be expected and how quickly and pervasively alternatively-fueled vehicles such as plug-in electric hybrids or hydrogen fuel-cell-powered vehicles will enter the market place. The research, as initially envisioned, would update the 2003 study to provide information useful to AASHTO and the DOTs.
STATUS: AASHTO staff and the NCHRP 20-24 project panel agreed in April 2009 that results of other research and rapid changes occuring as policy makers grapple with issues of greenhouse gas emissions, global warming concerns, and the future of the U. S. automobile industry substantially eliminate the motivation for this project as it was initially described.