...HTF Is Currently Unsustainable: The federal gas tax is the major source of revenue for the federal highway trust fund (HTF), but this has not been raised since 1993. Since 1993, demands for federal transportation funding continued to grow, causing a large imbalance between receipts into the HTF and outlays. The HTF relied on nearly $60 billion of general fund transfers since 2008 to maintain authorized funding levels. Higher corporate average fuel economy (CAF+) standards requiring greater vehicle fuel efficiency in the next decade will further complicate funding the HTF almost entirely through the gas tax. Long-Term Solution Unlikely Soon: Current transportation authorizing legislation, Moving Ahead for Progress in the 21st Century (MAP-21), expires Sept. 30, 2014 and a long-term solution prior to its expiration is doubtful. It is apparent additional revenue source(s) are needed just to maintain current transportation funding levels. Multiple potential revenue sources have been proposed...
