The deadline for the federal government to replenish the Highway Trust Fund is swiftly approaching, along with looming cuts to states' transportation budgets.

Secretary of Transportation Anthony Foxx is taking matters into his own hands. He sent a letter to individual states Tuesday morning stating that unless Congress acts before Aug. 1, the federal DOT will take steps to better manage the trust fund's cash flow — steps that will result, on average, in a 28-percent drop in federal transportation funding to the states.

DOT's new cash management system will stop paying each transportation bill as soon as it is submitted and instead will start a bi-monthly payment process as funds from the federal gas tax roll in.

Foxx says the worst part will be the long-term projects that never get started, rather than the projects that are put on hold this summer.

Several transportation funding bills have been talked about on Capitol Hill, but none have been passed.

Foxx's letter to state transportation chiefs is a call to action for Congress. The transportation secretary says lawmakers can still act when they return from their recess next week.