Under the Roadway - Inspiration from Bethesda Terrace

It seems to be an article of faith among many contemporary planners that grade separation is an
ti-pedestrian and inherently anti-urban. In practice, this has been the case all too often; pedestrians have been forced to use uncomfortable overpasses and underpasses, diverted from a direct route to a grossly inferior detour. It is indeed a miserable experience when you're forced to climb steep stairs to walk across a narrow concrete pad over noisy traffic with a sharp wind cutting through the chain link fence, or to pass through a claustrophobic, musty, tunnel adorned solely by the exposed electrical conduit for the dim lights. Yet when we accept these bad places as our model for grade separation, we forget the concept's original vision and early success. This troubles me again each time I visit Central Park.

The ideas and work of Frederick Law Olmsted set much of the foundation for urban planning. His transverse roads in Central Park continue to successfully overlay a rustic park environment on a busy street grid. They make it possible for an expansive urban park to coexist with the city's street system. This is the baby we should not throw out with the bathwater.

And then there's Bethesda Terrace, the architectural showpiece of the park. It is an amazing progression of space, a place that is experienced by movement through a sequence of spaces. Grade separation here is not some mere functional layout. It is not just a safety feature. The experience of descending, the transition through a dark, constrained space that frames the view of the Angel of the Waters, and the reemergence into the open, sunny space is the design.

The stairs from the Mall down below the roadway toward Bethesda Terrace

The architectural space below the roadway

Pedestrians do not have to cross traffic on the roadway above (although it's light enough these days it's not much of an issue)

The site conditions are somewhat atypical, with the change in elevation between the Mall and Bethesda Terrace. The level of investment in the architectural details is certainly on a scale that can only be justified for a signature space in a central location that can be enjoyed by everyone and can't be reproduced on a mass scale throughout a city. Yet this design should inspire planners to consider the way grade separation might enhance urban design in other places, rather than naively accepting any simplistic doctrine. There is much potential when it is designed to serve the needs and interests of pedestrians, rather than simply keeping them out of the way. Think broadly about the opportunities to create enjoyable experiences, rather than applying simple formulas.