What is the term for the form of circulation space that may be enclosed or open on one or both sides?

The correct term for the form of circulation space that may be enclosed or open on one or both sides is "Path." In architectural and urban planning contexts, a path refers to routes that pedestrians or vehicles take to navigate through a space. These circulation routes are essential in the design of buildings and landscapes, as they facilitate movement and accessibility while also influencing how users experience the environment.

Paths can take various forms, including corridors, walkways, or streets, and they can be either enclosed structures (like hallways) or open (such as sidewalks). The flexibility of being enclosed or open allows for the integration of natural light, airflow, and views, enhancing the overall ambiance of the space.

Other options like pass-by spaces, which refer to areas where individuals can stop briefly and interact, or grids, which refer to layout patterns for streets or plots, do not specifically describe circulation routes in the same manner as paths do. While terminating in a space can indicate a space where a path leads to a destination, it doesn't capture the essence of circulation itself as effectively as the term "Path."