The Virginia Department of Highways and Transportation has issued its spring highway construction report. The following is a list of the road improvements under way in the Northern Virginia area:

* I-66 in Fairfax and Arlington counties: Installation of traffic control system between Capital Beltway and Potomac River. Estimated completion date: 1984.

(The highway department urges motorists to be on the watch for small groups of workmen and equipment and to be prepared for small detours around work areas.)

* I-395 in Fairfax and Arlington counties: Installation of traffic control system between Capital Beltway and Potomac River. Estimated completion date: 1984. (Watch for small groups of workmen and equipment and follow detour signs around work areas.)

* I-66 in Fairfax County: Parking lot at West Falls Church Metrorail station. Estimated completion date: fall 1983.

I-95 in Alexandria: Reconstruction and replacement of concrete deck on Woodrow Wilson Bridge over Potomac River. Estimated completion date: spring 1984.

(Six traffic lanes reduced to one lane in each direction 8 p.m. to 6 a.m. Monday through Thursday and 9:30 p.m. to 7:30 a.m. Friday.)

* I-95 in Prince William County: Expansion of interchange and adjacent highways for the Dale City interchange. (Two-lane traffic maintained in each direction.) Estimated completion date: mid-1983.

* I-95 in Prince William County: Widening four-lane road to six lanes between Chopawamsic Creek and Triangle for 2.9 miles. (Two-lane traffic maintained in each direction.) Estimated completion date: late 1984.

* I-95 in Stafford County: Widening from four to six lanes and expanding the U.S. Rte. 17 interchange north of Fredericksburg, between the Rappahannock River bridge and Cranes Corner for 3.8 miles. (Two-lane traffic maintained in each direction.) Estimated completion date: late 1984.

U.S. Rte. 1 in Prince William and Fairfax counties: Construction of a northbound bridge at Woodbridge. Estimated completion date: mid-1984.

* Rte. 123 (Ox Road) in Fairfax County: Widening from two to four lanes between Fairfax Station and Marlborough Road for 1.4 miles. Estimated completion date: late 1983.

* Rte. 29 in Fauquier County: Constructing two lanes of a future four-lane roadway east of Warrenton on new location as part of the Warrenton bypass for 3.5 miles. Traffic will use existing route. Estimated completion date: 1984.

* Alexandria: Constructing four-lane roadway and bridge over Southern Railway tracks on Van Dorn Street, between Eisenhower Avenue and Pickett Street. Estimated completion date: mid-1984.

* Town of Culpeper: Constructing a culvert to replace a bridge over Mountain Run near Culpeper shopping Mall on Old Brandy Road. Estimated completion date: fall 1983.

* Leesburg: Rte. 7 (Market Street). Widening from two to four lanes between bypass and Catoctin Circle. Estimated completion date: mid-1983.

* Manassas: Rte. 234 (Grant Avenue). Constructing a four lane underpass at the Southern Railway tracks between Center Street and Prince William Street. Estimated completion date: fall 1983.