In which two places can an officer stand while directing traffic?

An officer can effectively direct traffic at a corner or intersection due to the strategic importance of these locations in traffic movement. Corners and intersections are where various traffic flows converge, making them critical points for managing vehicle and pedestrian interaction. By positioning themselves in these areas, officers can maintain visibility and authority, ensuring that traffic adheres to signals and signs, thus enhancing safety for both drivers and pedestrians.

This choice emphasizes the role of visibility and control in traffic management. Officers can observe all directions of traffic movement and respond quickly to any emergencies or violations that may occur. In contrast, the other options might not provide the same level of operational efficiency and safety. For instance, standing on a highway or overpass could pose significant safety risks given the high-speed nature of those environments. Similarly, parking lots or driveways may not involve complex traffic dynamics in the same manner as intersections do, and being on a sidewalk or median strip may limit the officer's visibility and control over the traffic flow.