Downtown Los Angeles, especially Bunker Hill, is a 2.5-D City. For example, the 5th floor of the Westin Bonaventure Hotel directly connects the ground level of the Ketchum-Downtown YMCA/Westin Bridge as a seemingly coplanar surface. Furthermore, the experience of walking from the YMCA to the Bradbury Building would make up the elevation drop of Angels Flight without ever leaving the datum by taking an elevator, staircase, or ramp. The richness of the 2.5-D quality about Los Angeles is primarily visible from the Westin Bridge– above, below, and between the pancakes of infrastructure, there are secret pockets to be studied amongst the many layers.
The Westin Bridge is high above the road beneath but it directly connects the pedestrian to the rest of the ground plane.
The base-level beneath the Westin Bridge, however, is in itself another datum. The history of Bunker Hill almost sculpts this 2.5-D relief condition for humans to navigate around, resulting in excellent visual and physical connections and disconnections.
Overlooking the parking structure beneath the Ketchum-Downtown YMCA, one would realize the layered datums that allow for relatively private activities to take place between the layers.
The street pattern below the bridges form a rhythmic grid, like two layers of lace superimposed over one another at an urban scale.
Like a highway overpass or underpass, the 2.5-D quality is more landscape-like than it is urban-like. It more closely resembles a geological condition than an urban one.
Between bridges, pedestrians may be separated by a river of air beneath them, even though they technically share the same conceptual datum.
Like cliffs that cut off paths, the broad vertical surfaces form visual opportunities for bypassers to experience.
An urban section through Bunker Hill would reveal the landscape quality of the continuous and discontinuous paths.
A time-based aligning of datums would also reveal that despite the feeling of never leaving the ground, the 2.5-D quality of DTLA deceptively lifts the pedestrian off the ground.
