RICHMOND, FEB. 16 -- Northern Virginia legislators won key votes today for innovative proposals that would permit a privately owned for-profit extension of the Dulles Toll Road and the creation of a small claims court in Fairfax County.

The full Senate, acting one day after committee action, gave its blessing to the 17-mile toll road extension from Dulles International Airport to Leesburg by a vote of 33 to 5. But first, members of the Northern Virginia delegation had to field questions about the project for more than an hour, many of them reflecting wonderment at what one rural senator called "NoValand."

Sen. Dudley J. (Buzz) Emick Jr. (D-Botetourt), whose district is a bucolic six-hour drive from western Fairfax County, asked of the toll road, "What's the rush?"

Similarly, in the House of Delegates, legislation that would permit the state's first small claims court passed 74 to 24, but not before a lawmaker from far Southwest Virginia denounced the idea of a new court as "an aberration."

"Maybe that this is in Fairfax has something to do with it," said Del. Ford C. Quillen (D-Scott), "but the concept is wrong." Quillen's district is closer to Nashville, Tenn., Frankfort, Ky., and six other state capitals than it is to Richmond.

The legislation would permit Fairfax County residents to pursue claims up to $1,000 in the new court, which would have relaxed rules of evidence. Currently, Virginians must pursue all claims regardless of size in a district court and usually must hire a lawyer to do so.

The complicated and unusual toll road proposal will be considered next by the House roads committee; some of its rural delegates have difficulty relating to the Washington region's growth and traffic problems.

Emick said that even the sponsor of the measure, Sen. Charles L. Waddell (D-Loudoun), was reduced to "reading speeches on the floor written by lobbyists . . . in $500 Brooks Brothers suits" who were hired by the backers of the road. Emick predicted that the project will produce "immense profits for land developers."

"This is not a bunch of private entreprenuers going wild," said Sen. Clive L. DuVal 2d (D-McLean), but rather "a magnificent marriage of public and private interests."

DuVal said the toll road's profits would be regulated by the State Corporation Commission, which prompted Emick to note that DuVal had criticized the SCC for permitting too high a return on investment for Virginia Power and other electric utilities.

Sen. Richard L. Saslaw (D-Springfield) called the privately financed toll road "a good example of privatization" that would allow more tax money to be spent on highway projects in others areas of the state.

The legislation establishing a small claims court in Fairfax County as a two-year experiment passed the House by a wider margin today than it did last year. Further, longtime sponsor James H. Dillard II (R-Fairfax) expressed optimism about the prospects of his bill in the Senate.

"I don't think Hunter's going to kill it this year," said Dillard, referring to Sen. Hunter B. Andrews (D-Hampton), who last year used his clout as Finance Committee chairman to scuttle the legislation.

Dillard, who has not given up the fight for a small claims court in more than 10 years of trying, said the ascension of Sen. Edward M. Holland (D-Arlington) to the chairmanship of the key Senate Courts of Justice Committee also may improve the bill's chances.

Dillard asserted on the House floor that the small claims experiment would cost the state nothing. Virginia and Tennessee are the only states without a small claims court.

Del. Harry J. Parrish (R-Manassas) was the only Northern Virginia delegate to vote against Dillard's bill.

As the Senate and House slogged through hours of debate before a midnight deadline to vote on their respective members' bills, neither chamber seemed to be in a mood to reject proposals.

"If you think this is bad," lamented Sen. Moody E. Stallings Jr. (D-Virginia Beach) during a vain attempt to defeat one proposal, "wait until you see what's coming."

The only legislation the senators rejected -- a proposal to give financial help to rural Pittsylvania County after it lost much of its tax base through annexation by the city of Danville -- received a 21-to-19 majority but failed because, as special legislation, it needed 27 votes to pass.

The House modified a measure backed by Lt. Gov. L. Douglas Wilder that would have denied any chance of parole to convicted murderers who avoid the death penalty. The House voted 95 to 2, with Speaker A.L. Philpott (D-Henry) against, to extend from 15 to 25 years the minimum prison time that must be served under a life sentence.

Also, the House gave overwhelming final approval to a Chesapeake Bay cleanup bill supported by Gov. Gerald L. Baliles and to state Attorney General Mary Sue Terry's proposal for the creation of a felony offense that could be brought against motorists who kill others while driving drunk.

In other action today, the Senate passed and sent to the House legislation that would:

Grant one year of in-state college tuition to dependents of nonresident military personnel stationed in the state. The vote was 27 to 13.

Require nonfarm trucks to cover their loads, 30 to 9.

Create local judicial nomination commissions, which would include nonlawyers, to recommend to the assembly candidates for judgeships, 27 to 13.

Remove adultery as an absolute barrier to alimony (Virginia is the only state with such a law), 22 to 17.

With 3 1/2 weeks remaining in the 1988 session, the legislature now will turn its attention to Baliles' $22.5 billion biennial budget.