Trails. Bicycle trails. Hiking trails. Horseback riding trails. Motorcycle trails. Trails for commuting and recreation. Trails that "go someplace" are what Northern Virginia needs most, according to speakers at seven of the eight public hearings held during the past two months by the Northern Virginia Regional Park Authority.

The park authority, which has preserved 8,000 acres of open space in the crowded suburbs of Northern Virginia over the past 20 years, will hold its final hearing in Arlington tonight on long-range park needs.

"What we need is a countywide trail system, not just trails inside parks but trails to get to parks, schools, shopping centers," Lorraine Foulds of Mason Neck told the park authority at last week's hearing in Mason Neck below Mount Vernon. "I live in the Mason District, not but a mile away from a store. But I can't get there without driving a car . . . Remember you have more people with feet than with cars. Give them paths to use them on."

Foulds has been thinking about paths and bike trails for more than a year now as chairman of her area's county-appointed trails committee. But dozens of other Northern Virginia residents, at all seven of the park authority's hearings, have surprised officials by calling for the same thing.

Mary Margaret Goodwin, president of the Mason Neck Civic Association was one of two speakers at last week's hearing urging a bicycle trail along Gunston Road to the park authority's popular Pohick Bay Regional Park and its giant swimming pool. "Our children need to get there safely on bicycles, without parents having to drive them. And we need it very shortly, not in the far distant future," she said.

The hearing in Herndon in Janaury brought pleas fro trails near schools to allow children to walk or bike to school, trails to enable four pony clubs to ride to equestrian classes, loop trails near Great Falls for horseback riders, roads for joggers and bicyclists.

Similar hearings in Leesburg, Fairfax City, Falls Church and Alexandria heard requests for bike, horse, motorcycle, and canoe trails (" . . . in streams . . . trails don't have to be just on land.") and feeder bike trails leading to the park authority's major new 42-mile Virginia Creeper Trail along the abandoned Washington and Old Dominion Railroad right of way from Alexandria to the Blue Ridge mountains. The 100-foot railroad right of way is to have both a paved bike trail and, west of Vienna, a parallel horse trail. It will connect with almost every major bicycle trail in Northern Virginia and numerous horse trails.

In addition to trails, requests were made for a major sailboat marina on the Potomac near Occoquan and a crew rowing complex near Roosevelt Island and Key Bridge and an urban park along Alexandria's Cameron Run Valley (with a bike trail through it.) The hearings also have brought requests not to do things . . not to build a road and miniature golf course at the largely natural Algonkian Regional Park along the upper Potomac and not to overdevelop Mason's Neck.

Perhaps the single most popular request, after trails, has been for soccer fields, including a proposal for a central Northern Virginia soccer complex with half a dozen game fields and locker rooms. More than 50,000 children in the metropolitan Washington area now play soccer during spring and fall.

But the persistent plea for trails at the hearings supported recent park authority moves to build long-distance trails, and will be used as a guide to future development within its park holdings.

Just last year the park authority completed a 14-mile horse and hiking trail along the Occoquan Reservoir, from Bull Run Park to Bull Run Marina, and ultimately plans to make it a 26-mile trail continuing along the reservoir's edge down to the town of Occoquan.

Acquiring the W&OD railroad right [WORD ILLEGIBLE] from the Virginia Electric Power Co., which the park authority signed an option on last December, is "one of the most historic things we've ever done," according to Walter L. Mess, founding member and chairman of the park authority, who has attended all of the recent public hearings.

The 42-mile trail to be built along the right of way is expected to become the major bicycling artery to which all other area bike routes will connect, and to a smaller extent a major long-distance horseback riding route.

However, the park authority cannot do much about the numerous requests for trails along roads because a bicycle path, like a sidewalk, usually is something only the county and state can build because they own the highway rights of way.

Local trails committee chairwoman Foulds criticized the state at last week's hearing for not having a trails coordinator, as many states do, and for using little of the federal highway funds the state receives for bikeways.

Since 1973, under the federal highway aid program, Virginia is eligible to use up to $2.5 million of the more than $200 million a year it receives in federal highway funds for separate bikeway projects (it has never used any) and can also use whatever amount it deems necessary to build bikeways in conjunction with road projects, just as it allocates funds for sidewalks.

Until the past few years Virginia had not built or even considered bikeways, says assistant state urban engineer James K. Skeens, but the state now weights the need for a bikeway on every road project throughout the state and is about to build at least two in Alexandria, just under a mile on a road-widening project along King Street (Route 7) near Interstate 395 and almost two miles along Duke Street (Route 236) east of Cameron Station.

The State also is putting a bikeway along portions of I-66 now being built and is constructing bicycle bridges over the Beltway and I-66 for the W&OD bike trail.