Designing a Connection
By: Lucas E. Shubert
My thesis involves a high percentage of outdoor space meant for pedestrian and bicycle traffic. Some of this space directly connects to vehicle traffic, and some of it does not. The most prominent piece of exterior built environment to be included is an underpass that connects the east and west sides of the rail line in Carbondale. There is a dramatic change in elevation from both ends of the underpass to the middle, beneath the rail line. There is no vehicular traffic in this underpass, so interaction on that level is not a design concern. However, this underpass does have a number of site and programmatic conditions to satisfy, in order for it to function successfully.
The most obvious condition that must be fulfilled is open access for pedestrians, bicycles, and wheelchairs. This is a difficult design challenge because of the sixteen foot change in elevation involved. The length of the underpass allows for an approximately twenty percent grade. That grade will allow bicycles to go up and down the ramps on either side, on a dedicated line, without too much effort to make them avoid the underpass altogether. Wheelchairs and bicycles will not share the same surfaces, creating the need for an additional dedicated pathway. Wheelchair ramps will have to change directions several times to avoid stretches that are too long and difficult to manage. There is also a basement level stair and elevator connection between the underpass and two adjacent buildings that create easy wheelchair access.
The second design condition is an aesthetic and functional engagement in the underpass. First, some questions have to be answered. Who will be using the underpass and do they want to spend any more time than they have to within it? The answers to these questions can change dramatically depending on design. For example, an element such as a stepping fountain cascading down the slopes that connect to a pool in the bottom of the underpass would create a more calming and comfortable experience. On the other hand, a smaller, tighter underpass with boring could result in a feeling of discomfort for users. Another example that could connect the bottom of the underpass to the site above is allowing clear sight lines to the adjacent buildings on and around the site by excavating channels.