OFFICIALLY IT'S only part-time work, away from home, but representing Northern Virginia in the General Assembly is an important, continuing responsibility -- made all the more significant by the additional functions that the federal government has been bequeathing to the states. For the most part, Northern Virginia's bipartisan delegation to Richmond has been rising to that challenge, becoming far more effective over the past four years than it used to be. The members have been working well with the governor and various legislative delegations to secure financing for transportation and other projects. As it was in the last house of delegates elections two years ago, this kind of coalition, experience and seniority is valuable, and speaks strongly for the reelection of most incumbents.

As it happens, there are a dozen incumbents from Northern Virginia who are unopposed. Among those deserving special mention for their notable service and/or key committee assignments are Sens. Wiley F. Mitchell (R) and Richard L. Saslaw (D) and Dels. Mary A. Marshall (D), Robert E. (Bob) Harris (R) and James H. (Jim) Dillard (R).

In the contests for state senate, the best race in terms of content -- intelligent, informed debate that has focused on solid issues -- has been between two respected candidates in the 32nd District: Democrat incumbent Clive L. DuVal 2nd and Republican challenger Bobbie Kilberg. The candidates have much in common. Both are graduates of Yale Law School who came here to work for Republican administrations and who moved into private practice, local civic work and state politics. Mrs. Kilberg contends that Mr. DuVal -- who is dean of the Northern Virginia delegation -- has a record of "going along to get along," and has not succeeded in securing a "fair share" of transportation money for the region. But Sen. DuVal's 22 years in the legislature gives him exceptional experience, seniority and influence -- all valuable assets in Richmond. Though Sen. DuVal is not a flashy wielder of power, he has been far more than a follower. He has delivered with distinction. Mrs. Kilberg's intelligent challenge this time could serve her well in the future. But Sen. DuVal's distinguished service to this entire region has clearly earned him another term.

In the 31st District, incumbent Democrat Edward M. Holland is a knowledgeable and respected four-term veteran of the state senate. His expertise in transportation and education -- top issues in Northern Virginia -- make him a far stronger candidate than Republican challenger Joseph Vasapoli. In the 34th District, Democratic challenger Emilie Miller, who lost a close race last time to Republican John W. Russell, should get a turn at the job. Mr. Russell's profile has been low to invisible, enough to impair anything resembling political vision. Mrs. Miller has political and legislative experience gained when she served as an aide to Mr. Russell's predecessor, longtime Sen. Adelard L. (Abe) Brault, and her party ties give her a decided edge in dealings with Gov. Gerald Baliles. In the 36th District, incumbent Democrat Joseph V. Gartlan Jr.'s intellect and independence have earned him the respect of political adversaries as well as allies, and the campaign of Republican challenger C. Ronald Smith has not presented any reason for voters to turn away from their most able senator.

For the house of delegates, incumbent Republican Robert T. Andrews of District 33 has performed valuable service for the region on the road committee. In District 34, incumbent Republican Vincent F. Callahan Jr. continues to bring expertise and seniority to the important work of the house -- topped by the good standing he has earned with Democrats. In District 35, the return of Democrat Dorothy S. McDiarmid, Northern Virginia's senior house member, is important to the entire region. In District 37, there has been a spirited contest between two strong contenders, Democrat Jeffrey J. Fairfield and Republican Jane Woods, for the seat being vacated by Republican Stephen E. Gordy. On the basis of energy and breadth of civic interests, Mrs. Woods would appear to have an edge.

In District 38, incumbent Democrat Leslie L. Byrne has served well in her first term and clearly deserves another. In District 39, incumbent Democrat Alan Mayer has learned the ropes in Richmond quickly and well. In District 45, incumbent Democrat Marian Van Landingham continues to represent her constituents and the region with vigor, intelligence and valuable experience. In District 46, incumbent Democrat Bernard S. Cohen has faced a challenge that is without substance; he should be reelected. In District 47, incumbent Democrat James F. Almand is a veteran legislator whose intelligent, researched approach to issues has been invaluable to all of Northern Virginia. And in District 48, incumbent Democrat Warren G. Stambaugh continues to be an influential advocate for the region, with 14 years of service in the house.