Congressional negotiations over a $200 billion-plus bill to pay for national road, bridge and mass transit projects for the next six years stalled on two key points Friday, an aide to the chief Senate negotiator said.

House negotiators refused to accept a Senate proposal to trim $9 billion in special-project spending to a figure in the $5-6 billion range. Critics call those projects pork.And Senate negotiators refused to yield on their plan to withhold 10 percent in highway money from states that do not lower their drunken-driving threshold to a 0.08 blood-alcohol concentration. The House negotiators favor only giving states incentives to make the switch from 0.1.

"They are meeting again (Saturday), but I anticipate this will be a problem and that passage for next week is very much in jeopardy," said Nicholas Graham, spokesman for Sen. John Chafee, R-R.I., chairman of the Senate Transportation Committee.

Earlier Friday, Transportation Secretary Rodney Slater warned states could lose jobs and an entire construction season if Congress doesn't vote on the bill before it starts its Memorial Day recess next weekend.

"We're talking about real jobs, we're talking about real projects, we're talking about real people - and we're talking about real pain," Slater said as he drove between sites that would be affected by a delay.

The American Society of State Highway and Transportation Officials has estimated that 1,400 projects valued at $2.5 billion will be affected if the legislation is not enacted by July 1. The group estimates that could cost up to 100,000 jobs nationwide.

The bill is one of the biggest spending measures Congress will deal with this year. Aides said negotiators for the separate House and Senate versions have made considerable progress and still planned to meet through the weekend in hopes of having a compromise ready early next week for floor votes in both houses.