Newly released figures show that the U.S. Department of Transportation's Highway Trust Fund could run out of money as soon as August.

On Tuesday, data posted on the department's website showed that there was $8.3 million in the account, which is used to pay for many U.S. road and bridge projects.

The account had a balance of $1.6 billion in October, the beginning of the fiscal year. Another $9.7 billion was transferred into the account from the General Fund. But expenses have outpaced revenue and are projected to do so as the heavy construction season begins. The account's balance has dropped $3.7 billion since the transfer occurred.

The Highway Trust Fund gets its revenue from gas taxes of 18.3 cents per gallon on gasoline and 24.4 cents per gallon of diesel fuel and related excise taxes. The tax has not been raised in nearly 20 years not kept pace with inflation.

Without money, the department would not be able to reimburse states for construction projects.

Late last year at the Transportation Research Board's Annual Meeting in Washington, DC, Secretary of Transportation Anthony Foxx announced that the DOT would begin posting monthly on its website exactly how much money the Highway Trust Fund has left, and update that number every month until the fund can sustain itself or until it runs out. While the DOT has long provided this figure to Capitol Hill, Foxx said providing it to the public would increase transparency and accountability.

The department's Mass Transit Account isn't doing much better. Projections show that account will have $440 million at the end of the fiscal year in September. It began the fiscal year with $2.5 billion and was bolstered with a $ billion transfer of funds from the General Account.

As of the last week of January, the Mass Transit Account had a balance of $3.3 billion.