Van Dorn Street continues northeast as an unnumbered street to its end at SR 7 on the boundary between Alexandria and Arlington. Access from Van Dorn Street to SR 420 is provided by a pair of intersections with Kenmore Avenue that lead to a pair of right-in/right-out intersections with the overpassing highway.
North of SR 236, the state highway becomes an undivided highway, crosses Holmes Run, and begins to closely parallel I-395 (Henry G. Shirley Memorial Highway). SR 401 continues northeast to a point within SR 420's (Seminary Road) overpass of the highway and the latter highway's three-level diamond interchange with I-395.