WASHINGTON — Congress has approved a bill to prevent a 28 percent cut in federal highway and mass transit aid at the height of the summer construction season.

The Senate voted Thursday night for a House-passed measure to augment the federal Highway Trust Fund with in infusion of $10.8 billion from the general Treasury — enough to keep the fund solvent through May. The Transportation Department set Friday as the date the fund would no longer be able to provide all the aid promised from incoming gasoline and diesel fuel taxes.

The two houses played legislative ping pong with the issue in recent days over what critics called a “gimmick” to fund the measure by letting companies defer government-required contributions to their employees’ pension plans. The bill now goes to the president.