RICHMOND, FEB. 3 -- Northern Virginia legislators are always seeking ways to relieve traffic congestion, but Del. John A. (Jack) Rollison III (R-Woodbridge) is adding a new dimension to the issue.

He wants to alleviate the long lines that often develop outside women's restrooms, an issue that has come to be known here as "potty parity," and has introduced a resolution that could lead to larger restrooms and more toilet stalls for women in public buildings and arenas throughout Virginia, and even beyond.

Rollison said he had taken up the cause of "restroom equity" at the prodding of his wife, Lawrie, and his legislative aide, Bonnie Campbell, who complained to him, "There oughta be a law."

As part of his campaign, Rollison plans to use the results of a study being conducted at Virginia Tech that seeks to answer the question, so often voiced by men, "What took you so long in there?"

Clutching a blue-bound copy of the International Plumbing Code, Rollison tolds a news conference today that his resolution calls for the state's Department of Housing and Community Development to conduct hearings around the state and deliver the results to the 1989 mid-winter conference of the Building Officials and Code Administrators International. That group establishes criteria for restrooms in a number of Northeastern and Midwestern states.

To garner support, Rollison addressed the legislature's Women's Roundtable, and signed up cosponsors including Sen. Emilie F. Miller (D-Fairfax) and Dels. Leslie L. Byrne (D-Fairfax), Gladys B. Keating (D-Franconia) and Jane H. Woods (R-Fairfax).

Current law requires new public buildings to contain an equal number of water closets in men's and women's restrooms, but Rollison said the regulations apparently don't take into consideration how much the use of urinals speeds things up.

Also, he said, demographics are changing the needs. With more women in the work place, more are using public restrooms.

The Virginia Tech study is financed by two grants totaling $1,300 and conducted by Savannah Day, a professor of housing, and Sandra Rawls, whose doctoral dissertation is about "patterns of behavior in the use of male-female restrooms."

They have been interviewing people outside restrooms at the Roanoke airport, at a rest stop on I-77 on the Virginia-North Carolina border, and at Tech's coliseum and continuing education center.

"We don't follow people inside," Day emphasized, but her team records the length of stay and asks a series of questions as they leave.

Women attributed their longer stays -- sometimes nearly twice as long as those of men -- to having more clothes to manipulate than men; having children with them, and to taking time to comb hair, adjust makeup or to talk or smoke.

As for men, their only complaint, Rawls said, is about those automatic blowers. "They all want paper towels, better paper towels."

Day said she decided to conduct the study after she missed a plane at the Atlanta airport.

"The pilot assured me I had time to go to the restroom," the professor recalled, but when she finally got out, the plane was full.