Client/Owner: National Park Service

Description: One intention in creating the George Washington Memorial Parkway was to preserve views to the Potomac River Gorge. When the aging Parkway needed rehabilitation, receipt of Federal Highway Administration funding for the project required that current safety standards be incorporated. The historic stone masonry walls lining the Parkway, and framing the views to the Potomac River Gorge, had not been tested for crashworthiness, and were not of adequate height for today’s traffic speeds. In order to facilitate the process of striking a balance between current transportation safety standards and preservation of historic resources, G&O implemented some creative techniques, including innovative viewshed mapping of the project area, and a 3D video simulation of potentially higher walls and guardrails. G&O also conducted a Cultural Landscape Inventory, including GPS mapping of several contributing resources.

Significant Facts:

• To capture the relationship of the historic stone masonry walls with views to the Potomac River Gorge and beyond, G&O videotaped the length of the Parkway and created a 3D simulation with heightened guardwalls and guardrails.
• The viewshed study included still photography and GPS documentation of the stone masonry walls. The various views from the Parkway views were also numerically rated using a Bureau of Land Management viewshed analysis scale, and the techniques were combined to create comprehensive viewshed mapping.