The Highway Trust Fund, which collects and allocates money to build and maintain surface transportation structures, receives almost 90 percent of its funding from a fuel tax on gasoline and diesel, while remaining revenue comes from miscellaneous taxes on tires, heavy vehicles, etc. Since 1993 the fuel tax has not adjusted. Advancements in technology has led to a decrease in the amount of fuel consumed and thus a decrease in revenue. Additionally, the almost 25 percent of the revenue from the fuel tax is diverted away from highway spending.

The Highway Trust Fund itself is divided into two accounts—the Highway Account and the Mass Transit Account—and each account expends roughly 85 percent and 15 percent of the total funds respectively. Highway Trust Fund spending has routinely outpaced fuel tax revenue. For the 2015 fiscal year, the Highway Account is estimated to spend upwards of $44 billion on roadway infrastructure and similar projects while only taking in $34 billion. Including the deficit accumulated by the Mass Transit Account, the Highway Trust Fund is expected to amass a deficit of $13 billion by the end of the 2015 FY.

Because the Highway Trust Fund cannot have a negative balance and must have a $5 billion minimum balance to meet obligations, Congress must shift money from the Treasury’s general fund. Over the last six years, Congress has diverted general fund dollars to the Highway Trust Fund more than thirty times. These “patches” are short-term fixes typically lasting from six months to a year and do not represent viable options in the long run.

Proposals for sustainable solutions include:

• Increasing fuel tax
• Decreases non-highway spending
• Taxing the overseas earnings of multinational corporations (repatriation)
• Downsizing Federal role in transportation
• Additional State actions such as tolls, bonds, sales taxes

Click here for more information on how the Highway Trust Fund works.