The objective of this project was to support AASHTO efforts to analyze funding from the federal Highway Trust Fund (HTF) and other sources to better estimate the potential levels of federal highway and transit resources in the future, with particular attention to estimating the implications of instability in the federal surface transportation program.  The research updated AASHTO’s Highway Trust Fund (HTF) Model to estimate more accurately and efficiently the levels and potential impacts of the federal highway and transit resources in the future. The research team also provided expert support for selected AASHTO meetings related to development of the organization’s policy positions on funding and finance and prepared briefing materials on specific funding and finance issues. All research products were delivered to AASHTO for member and staff use.