A proposed east-west highway in the Maryland suburbs, widening projects on Interstates 66 and 95, and several other major transportation initiatives in the Washington region are in line to receive tens of millions of dollars in federal funding, according to details of a congressional agreement announced yesterday.

Local governments have been counting on the money to advance projects that they said are critical to getting drivers and transit riders where they want to go.

Government officials and advocates for transportation programs had virtually begged Congress to approve the measure for the past two years, when the previous transportation funding legislation expired. A deal was worked out in a congressional conference committee, and White House support is likely.

Most sizable transportation programs rely on the federal government for most of their funding, and scores of initiatives have stagnated in the absence of a new spending measure.

The lack of a bill "has made it more difficult to do long-term planning because there's not been, for nearly two years, a long-term funding commitment from the federal government," said Virginia Transportation Secretary Pierce R. Homer. "Now it's in place, and we'll be in a position to start thinking about some longer-term projects, and that's good news."

The bill includes $33.6 million to improve the I-66/Route 29 interchange in Gainesville, $12.8 million to widen I-95 between Route 123 and the Fairfax County Parkway, $15 million to improve the interchange at Suitland Parkway and Route 4 in Maryland and $8 million for the intercounty connector, a highway linking upper Montgomery and Prince George's counties.

There is also $27.6 million to widen westbound I-66 inside the Capital Beltway, a proposal supported by many members of Congress but opposed by residents and local leaders in Arlington County. This year, state officials recommended adding a lane and estimated its cost at $112 million to $233 million.

"The improvements on I-66 are a must," Rep. Frank R. Wolf (R-Va.) said in a statement.

"The state needs to move as quickly as possible to open this choke point," he said.

The measure includes $100 million so Metro can buy 52 rail cars and language that authorizes a rail line to Dulles International Airport and a proposed link between Bethesda and Silver Spring, known as the Purple Line.

The money for Metro cars was a priority for the District, Maryland and Virginia. Their leaders said they are concerned about extreme crowding in the transit system.

Dan Tangherlini, Metro board member and District transportation director, said the money would enable Metro "to expand capacity on rail and begin to deal with the fact that six-car trains are right at capacity."

For Maryland, the bill also includes $21 million for a Silver Spring transit center, which is planned to serve Metro, buses and taxis; $11 million for a bypass around Hughesville; and $5 million to improve access to the Branch Avenue Metro station.

For Virginia, there is $8 million for traffic-calming measures at Gilberts Corner in Loudoun County and $1 million for more buses for the Potomac and Rappahannock Transportation Commission.

Homer praised Virginia's congressional delegation for choosing to get more money for a limited number of projects rather than spreading it thin.

District officials said they expected funds to help refurbish bridges over South Capitol Street and 11th Street but were unsure last night how much was included in the bill.

Despite enthusiasm over the agreement and the expected flow of funds, Lon Anderson, director of public and government affairs at AAA Mid-Atlantic, said the money would do little to relieve the crushing traffic Washington area motorists face each day.

"I am fairly underwhelmed," Anderson said. "Small amounts of money applied to major intersections and thoroughfares doesn't really accomplish much. When you're talking about $4 million or even $10 million for pieces of 95, it's little more than chump change."

Officials in Maryland and Virginia said they also stand to benefit from language in the bill that increases the amount of money that will flow to "donor" states, those that pay more in gas taxes than they get in return. Maryland and Virginia are donor states. The District will lose money under the formula change.