Jan Van Dyke seems to have come to a fork in the road. Reared in Washington and a choreographer and dancer since the mid-'60s, she's also been one of the prime movers of the attempt to establish a modern-dance constituency here. Forever wending up one path and down another, she now faces an uncertain future with a mixture of hope, anxiety and determination.

Before the future arrives, however, she will pass another career milestone with a novel, enterprising work premiering tonight at the Corcoran Gallery of Art.

The piece, "Dance in Two Spaces," was supported by a $4,790 choreographer's grant Van Dyke received this year from the National Endowment for the Arts, almost all of which will go toward paying salaries for her nine dancers. This isn't the first time Van Dyke has introduced a dance at the Corcoran. In 1975, she brought forth "Ella," a large group piece, mysterious and evocative in its dramatic contours and one of her most durable works. "Ella" will be restaged at the Corcoran tonight along with "Dance in Two Spaces," and the two will alternate in daily matinee performances throughout the week following.

"The piece was inspired by the Corcoran and the wonderful spaces it has," Van Dyke says. "As you enter the gallery you face the grand staircase, which is flanked on either side by a large atrium. The piece will happen in both these areas at once, with two groups of dancers, and a soloist, separated spatially and doing different things at the same time. I'm a little afraid some people may find it frustrating at the start, not being able to see it all, see the whole at once. I hope the audience will understand that it's an experiment, not only from the choreographic standpoint, but also an adventure in perception."

In form, the 20-minute "Dance in Two Spaces" will consist of four sections, to be danced in sequential order. The order for one group of dancers, however, will be exactly the opposite of that for the other, with the soloist as a link between the two, dancing first with one group and joining the other halfway through. The second group of dancers, in other words, will begin at the "end" of the composition, and proceed to the "beginning," at the same time that its counterpart group dances in the "normal" order.

This sort of serial counterpoint and temporal juggling has been much more common in musical composition, but it's rare in dance. "If, as a member of the audience," Van Dyke says, "you look just at one side of the work, you'll get one idea of it. Then if you look at the other side, you'll come away with another, different idea. And knowing both, you'll find still a third meaning emerging from the combination -- at least that's what I'm hoping will happen.

"The concept interests me a great deal -- the simultaneous reversal and fusion of the two currents. I think it's pretty risky though -- I don't know of anybody ever trying exactly this sort of thing before."

Van Dyke began to compose the dance just after Christmas, allowing about two months -- her more or less average need for a new dance work -- for completion. "This one was really nip and tuck, though," she says."Working with two casts simultaneously was a lot more pressure than I anticipated -- everything had to be doubled. I won't be dancing myself, though I originally intended to." Instead, Elly Canterbury, longtime Van Dyke associate and company member, will be the soloist.

Other problems added themselves to the usual hurdles of creative endeavor. The actual vocabulary of possible dance movements had to be rather severely restricted because of the gallery's hard and slippery marble floor. And Washington composer Steve Bloom, who did the score -- mostly percussion -- for "Dance in Two Spaces" and will perform it live during the Corcoran programs with a colleague, faced the dilemma of making a single piece of music that could support two different sets of dance steps at the same time.

Van Dyke also had to be mindful of her own precedent, "Ella," the strongly profiled piece she created for the same space four years earlier. "I was worried about making something too much like 'Ella'; I was also fearful the new piece might not live up to the old. I consciously tried to do something distinctly different, therefore."

Is the magical protagonist a surrogate for Van Dyke herself? A number of her works in the past have had decidedly autobiographical aspects. "I think all art comes from a deep place, and in that sense it's all autobiographical. The soloist in this dance does give one a sense of journey or passage, and that has particular meaning for me. I wouldn't want this to be a limiting factor when an audience looks at it, though -- it's not just my story, it goes beyond that."

Van Dyke sees herself going through a sort of transitional phase of late.

"I feel like my work has been changing a lot for the past two years or so," she says. "For a long time I had been making slow, serious, dramatic works. Somehow, when I had that retrospective concert in 1977 [it was also the year Jan Van Dyke and Dancers performed at Lisner Auditorium on the modern dance series for the first time] I felt I'd reached some kind of junction. Since then I've done the first pure movement piece I've attempted in a long time, called 'Fleetwood Mac Suite.' I did a piece at the Renwick [a kind of modern fable] that I didn't think was successful. I did that parade for the streets of Washington, which I really loved; 'Passenger,' a piece that came out of a deeply personal emotional experience; and 'Variations on a Theme,' which was very intellectually intriguing for me."

Certain commitments are firm. The Van Dyke troupe will be one of the groups performing in this year's "City Dance" festival in May, a showcase for area dance activity. The company is also scheduled to appear at the Milwaukee Art Center this spring, and Van Dyke herself has a six-week guestteaching and workshop engagement at the University of Hawaii in Honolulu coming up in July.

In the meantime, other objective circumstances may greatly alter her plans. The lease for the Dance Project -- the splendid Adams-Morgan studio and performing space which has been home not just for her own company but also a stimulating series of local and visiting dance attractions under Van Dyke's auspices over the last several years -- will be up in a year, and she's hearing rumors the rent will double, which would force her to vacate.

On the positive side, the Van Dyke company is one of the local groups proposed by the National Archives as occupants of the ground floor of the old abandoned Landsburgh's department store building, as part of a leasing and renovation plan submitted to the Pennsylvania Avenue Development Corp. And Van Dyke has had an encouraging talk with Kennedy Center Executive Director Martin Feinstein about the Center's new 500-seat Terrace Theater.

In the face of these possibilities, bad and good, Van Dyke is once again thinking of spending a spell in New York -- as she did before in the late '60s -- this time in quest of refreshment. "I'd just be going to test some new input," she says, "to learn again, to work with some people, take classes, I'm not sure. I feel I need to get a perspective on myself outside of Washington, at this point."

As for her future in Washington, she says: "There's been an amazing amount of growth in dance here, that's obvious, if only in quantitative terms. But many times I've wished there were more people around with goals similar to mine; I've often felt very alone here. I don't think there's been much understanding about a single artist trying to present his or her point of view.Audiences have been good, but the powers that be have given little thought to dance as an art form, as opposed to popular entertainment.

"One thing that I find promising is the work some of my students have been coming up with lately -- people I've worked with over the years, now producing good and valuable dance works. They're turning out to be the people I can feel the closest kinship with.

"I guess you'd have to say I feel very mixed about the potential in Washington's future, for myself, for modern dance -- it could go either way."