Urban Navigation

III. The Deflected Vista The deflected vista is a promise. Its job is to provide visual interest at key points along a line of movement, but in a way that clearly defers to a prospective goal. To succeed in this ambivalent task, a deflected vista provides an oblique or incomplete view of a frontal building. The most common technique is to angle the facade of a building relative to the axis of travel, creating a vanishing point outside the street walls framing the line of sight — quite literally around the bend. Such a composition displays an architectural equivalent to the gesture of a person bowing a visitor down a hallway, simultaneously offering a greeting and indicating where to go next. A second common technique is to have a building frontally encroaching into the line of sight, but only partly visible. The street axis is thereby incompletely terminated and implies that the ultimate goal of movement is still to come. In both techniques, it is sometimes possible to arrange the area plan so that an element of the final goal — perhaps a tower or dome — may be simultaneously visible above the street-level deflection. This combination of provisional and ultimate goals is called a layered vista and will be discussed more fully in the next Technical Page. DESIGN CONSIDERATIONS The deflected vista, when it occurs in orthogonal grid plans, always causes an angled geometric exception. The deflected vista made by encroachment, on the other hand, is easier to integrate because it requires only a slight slippage within the orthogonal system. It is easiest to design a deflected vista, or a set of deflected vistas (they often occur in multiples), along a line of passage that is permitted to vary in width and where there is no mandate that streetwalls be exactly parallel. The variability can be created directly by forming the street, but also indirectly by making blocks irregular or irregularly arranging regular blocks. Any one of these will infuriate orthodox traffic engineers. Since it is beckoning onward, a well-designed deflected vista will also have a measure to it. A rhythm made by vertical façade openings accelerates attractively when seen in perspective. To the contrary, a diagonal vista made by long horizontal elements such as balconies or strip windows is ineffective because it converges but provides no way to judge the pace of visual or anticipated bodily movement. Because façade details in a deflected vista are seen at an angle, a small amount of depth has a disproportionate effect. Effects of shade and shadow are exaggerated relative to those same details perceived frontally. This makes the design of the facades along a deflected vista a balancing act. The details must be demonstrative enough to mark a rhythm, yet not so bold or complex as to halt the implied sequence of progress. A deflected vista may fail because of too-deep details. Deflected vistas are in essence buildings and spaces gesturing beyond themselves. As such, they are not only useful and courteous, but signify allegiance to the idea of the city itself, the whole that is greater than the sum of its parts.