WASHINGTON - The U.S. Department of Transportation said yesterday that it would start limiting payments to states for road and transit projects next month in an attempt to conserve the federal Highway Trust Fund's disappearing cash.

WASHINGTON ó The U.S. Department of Transportation said yesterday that it would start limiting payments to states for road and transit projects next month in an attempt to conserve the federal Highway Trust Fundís disappearing cash.

Usually, the department reimburses states for transportation projects upon request. But beginning Aug. 1, states will receive funds only once every two weeks as money is collected through federal gasoline taxes.

The move might put pressure on Congress to approve at least a short-term fix before its August break begins. The DOT estimates that the highway fund will hit zero in late August, potentially idling several hundred thousand workers with midterm elections coming in the fall.

States will see, on average, a 28 percent reduction in funds.

Congress has only 16 working days before the August recess. Finding even a short-term solution might prove difficult. Last week, the Senate Finance Committee tried to move through a $9 billion plan to restore the fund through yearís end.

But that plan went nowhere after Republicans said it wasnít bipartisan enough.

Yesterday, Obama urged Republicans to take quick action, arguing that failing to do so could mean huge layoffs.

Information from The New York Times was included in this story.