Large parts of the Capital Crescent Trail are temporarily closed due to construction for a light rail line. It will reopen sometime in 2022. A local member gave us this detour:
Southbound: At turn J, turn right onto Jones Mill Rd., then immediately turn left onto Jones Bridge Rd. Go 1.7 mi. At Rockville Pike (also unsigned Wisconsin Ave.) turn left. Go 1.1 mi. At Bethesda Ave., turn right. Go 0.2 mi., then turn left onto signed Georgetown Branch Trail. The Trail is on the left just past the intersection of Bethesda Ave. and Woodmont Ave.
Northbound: At Bethesda Ave., turn right. Go 0.2 mi. At Wisconsin Ave., turn left. Go 1.1 mi. At Jones Bridge Rd., turn right. Go 1.7 mi. At 'T", turn right onto Jones Mill Rd., then immediately turn left onto signed Georgetown Branch Trail.
For a different signed detour see
http://www.purplelinemd.com/en/cctrail