Good news for Fairfax in related to the overpass of Route 7 over the Dulles Toll Road (DTR).
A 14 foot wide shared-use path will be built for pedestrians and bikes to travel in each direction. The shared-use path will tie into future trails. This will be similar to the system of trails that connect non-TOD Arlington, Westover, and Falls Church to the job centers of Arlington via the Custis Trail, a very popular trail in Arlington. The trail will take a few more years to tie into further out suburbs, but in the short term will provide access to many in the Wolf Trap vicinity (and possibly access for those of us in Tysons to Wolf Trap as well).
One interesting concept would have the trails converge on a central median zone once passing Jarrett Valley Drive and entering Tysons, which could have some interesting design possibilities. It would also provide the easiest implementation of existing right of way, as well as utilizing an otherwise wasted space underneath the metro line (we could call it a cycle track or bike highway like DC does and finally be cool like they are).