WASHINGTON — Virginia transportation officials recognized in the late 1990s that the growing stream of tractor-trailer rigs rumbling north and south along I-81 through the Shenandoah Valley would eventually clog the four-lane highway.

So they formally invited ideas for addressing the highway’s future needs.

The winning concept, submitted by a coalition of more than three dozen Virginia and national road-building, design and engineering firms, called for doubling the size of the interstate by adding four lanes solely for toll-paying trucks along the highway’s entire 325-mile Virginia segment.

What followed offers a glimpse of how much money can flow to a member of Congress willing to champion a congressional earmark, especially one that might conflict with state transportation policy.

The cost of the proposed toll road, in a state with huge demands for relieving traffic congestion in northern Virginia, was a nonstarter for state officials: $8 billion to $13 billion.

So the coalition, known as STAR Solutions, turned to politics, seeking earmarked funds to jump-start the I-81 project. It was well positioned with the Republican Congress, having retained the services of lobbyist and strategist Randy DeLay, brother of former House Majority Leader Tom DeLay, R-Texas.

They also fattened the campaign wallet of the man in the best position to help them — Alaska Congressman Don Young, chairman of the House transportation committee — with more than $240,000 in campaign contributions.

Executives and their spouses from many of the 40 companies in STAR Solutions — among them subsidiaries of Halliburton Co., Koch Industries and Ashland Oil Co. — donated $110,000 to Young’s campaign from 2002, when the group submitted its proposal, through 2005. The firms’ political action committees contributed another $93,000. Koch’s and Ashland’s PACs gave $37,900 to Young’s Midnight Sun leadership PAC.

One donor, Maura Dunn, chief operating officer of Halliburton subsidiary KBR Inc., was listed in Young’s campaign finance report to the Federal Election Commission as a ``homemaker.’’

Some of the money was collected at Young fundraisers — at an annual golf tournament at the Robert Trent Jones Golf Club in Gainesville, Va., and at an event he hosted at the elite Homestead resort in Hot Springs, Va., whose room rates can be as much as $700 per night and which boasts three championship golf courses.

In a House-Senate conference committee in the spring of 2005, Young inserted $100 million for a pilot truck toll-lane project on I-81 in Virginia, said Keith Ashdown, chief investigator for the nonprofit group Taxpayers for Common Sense.

But there was a catch. Federal law requires states to conduct environmental studies before altering an interstate highway.

Virginia Transportation Secretary Pierce Homer said he didn't ask for an earmark for 325 miles of truck lanes. He said he phoned Young, and the congressman agreed that, if the study rejected the toll lanes, Virginia could use the money to build ``climbing lanes’’ so that slower-moving trucks could move to the side on two dangerous, uphill sections of I-81.

The study ultimately concluded that adding four truck lanes wouldn't solve the problem, because ``there would be too much space for trucks and not enough space for other vehicles,’’ state transportation department spokeswoman Laura Southard said.

Christopher Lloyd, a representative of STAR Solutions, said the four-lane idea was just “a concept’’ and that his group will work with the state on whatever solution it pursued for I-81.

As for all the campaign donations, he said executives for the group had supported Young financially ``before, during and after the I-81 selection process.’’