update of the streetscape manual for the National Mall
Dear Mr. Acosta:
In its meeting of 20 June, the Commission of Fine Arts was pleased to hear two information presentations by the National Capital Planning Commission staff on the Monumental Core Streetscape Project and its proposed frameworks and policies for streetscape and lighting design, part of a comprehensive update of the Streetscape Manual for the National Mall Road Improvement Program. The Commission expressed appreciation for the efforts to revise the manual, and provided the following comments for its development.
Urban Design Streetscape Framework
In their discussion of the streetscape framework plan, the Commission members identified several issues for further study and clarification. At the broadest level, they advised that the plan should anticipate contemporary environmental issues, such as the impact of extreme weather and localized flooding, so that necessary adaptations of the streetscape can be planned for systematically, rather than on a case-by-case basis. They emphasized that the urban streetscape should be conceived of as a performative landscape system rather than as a composition of separate elements; they cited the presentation of classifying trees as distinct vertical elements, whereas the plan should consider trees to be a complex of living organisms requiring specific infrastructure to thrive within the streetscape. They also questioned the plan’s emphasis on the thresholds identified between the National Mall and adjacent precincts within the monumental core, commenting that the boundary drawn between the broader monumental core and the surrounding city may suggest the location of significant thresholds. They advised that the city’s major axial and diagonal roadways should be considered as the framework of the monumental city that reaches beyond the strict boundaries of the historic core, and they found that the streetscapes of these corridors should emphasize continuity. Accordingly, they suggested that the design approach to thresholds should derive from the identified hierarchy of street types, emphasizing either continuity or transition.
Street Lighting Policy and Framework
In consideration of the street lighting policy, the Commission members expressed general support for retrofitting the city’s existing streetlights with light-emitting diode (LED) lamps, noting the reduced energy consumption, improved color, and more consistent background against which important buildings and monuments can be lit. However, they cited the existing hierarchy between the white light of the monumental core and the warmer light of the surrounding city, and they expressed regret that this distinction may be lost when all streetlights are converted to the same color temperature; they suggested exploring ways to preserve this hierarchy. They noted that the spatial and architectural conditions of the city may be expressive enough without using street lighting to delineate the complex system of street classifications, and they therefore suggested simplifying the lighting framework. In general, they encouraged local and federal stakeholder agencies to consult with innovative urban lighting designers for the testing and implementation of this new street lighting technology, and they encouraged constructing in-situ mockups to test the criteria proposed in the policy.
The Commission looks forward to continued review of revisions to the Streetscape Manual as a product of the planning effort for the protection and stewardship of this nationally significant urban landscape and its infrastructure. For the development of the next submission, please consult with the Commission staff which, as always, is available to assist you.
/s/Thomas E. Luebke, FAIA
Marcel Acosta, Executive Director
National Capital Planning Commission
401 9th Street, NW, Suite 500-N
Washington, DC 20004
cc: Laurin Lineman, Federal Highway Administration
Jeff Marootian, D.C. Department of Transportation
Peter May, National Park Service