The 16th Street Circle is unique in many ways. The border between Washington, DC, and Maryland runs diagonallly through the middle of it. The intersection is therefore maintained separately by two different entities -- the Maryland State Highway Administration (MSHA) and the District Department of Transportation (DDOT).

To the north is MD 390 (16th Street) and to the northeast is MD 384 (Colesville Road), both maintained by MSHA. To the southeast is Eastern Avenue, to the south is 16th Street, and to the southwest is North Portal Drive NW -- all three of which are maintained by DDOT. Furthermore, to the northwest is a privately-maintained apartment building with an access onto the circle.

The geometry of the circle is a mix of traffic circle, roundabout, and siganlized couplet. On the Maryland side, MD 384 approaches as if approaching a roundabout -- they yield to traffic within the circle. However, MD 390 approaches as if a traffic circle -- traffic within the circle must yield to entering traffic. To further complicate things, the District side has signalized each of its approaches.

Pedestrian accommodations were at one time non-existent on the Maryland side, though concrete refuges have since been installed across the MD 384 and MD 390 legs. The Maryland crossings themselves remain unmarked. The District provides marked and signal-controlled crossings across Eastern Avenue, 16th Street, and North Portal Drive NW. The 16th Street pedestrian crossing includes a pedestrian signal to stop outbound traffic, with the pedestrian movement functioning as a two-stage pedestrian crossing.

The junction has been a source of complaints for a long time. MSHA is currently developing plans to signalise its two approaches, akin to the DDOT side. This would address safety concerns as well as provide for marked and signal-controlled pedestrian crossings, of which the MD 390 crossing is anticipated to include an outbound signal as per its 16th Street counterpart on the DDOT side.