Vivian Watts, Virginia's secretary of transportation and public safety, will discuss the future of roads in Northern Virginia during a free program tonight at Hidden Oaks Nature Center in Annandale.

Joining Watts in the discussion of "Highways and Other Ways" will be John Thillman, a member of the County Planning Commission, and Ed Risse, a leading developer in the area. The program, which begins at 7:30 p.m., is the concluding presentation of the "Crossing the Landscape" series of lectures sponsored by the Fairfax Park Authority's Division of Conservation.

Watts, Thillman and Risse all have considerable experience in transportation issues in the county and each brings a different perspective to the subject. Following their opening remarks, the panelists will address questions from the audience.

The Hidden Oaks Nature Center will be open an hour before the program at 6:30 p.m. The public is welcome to come early and see "The Making of the Fairfax County Landscape" exhibits at the center, which provide an historical context for the evening's discussion.

A model of the Rte. 50-Gallows Road interchange will also be on view as an example of the role of roads as a force in landscape change.

The center is in Annandale Community Park, 4030 Hummer Rd., Annandale, and can be reached by taking Beltway Exit 6-E (Little River Turnpike, Rte. 236) east, then left at first light at Hummer Road to the park entrance on the left. For more information call the center at 941-1065.