Cultural Landscape Report Baltimore Washington Parkway

Kelsch, Paul; Cortez, Amanda; Fettig, Jake; Rahimi, Rana; Schiavoni, Alexandra

This report documents the history and current conditions of the Baltimore-Washington Parkway (B-W Parkway). In doing so, it assesses the landscape’s historical integrity and proposes changes to meet highway safety concerns while maintaining and improving the historical integrity of the landscape. It focuses on a series of maps generated at three distinct scales that document conditions and design decisions that underlie the parkway’s structure and character. It also studies the parkway’s sequential experience through a series of sections that record the spatial sequence that drivers experience. Based on this documentation, it recommends specific design proposals in response to highway management and safety concerns identified by NPS personnel and others that emerged through this historical analysis. For most of its length, the B-W Parkway is a four-lane, divided roadway extending northeast of Washington, DC for nineteen miles through a forested corridor. The parkway originally was conceived as part of an unrealized proposal to create a national forest near the capital, and it connects several federal properties that collectively conserve much of the proposed forest lands. Forest defines the character of the surrounding vegetation, and its continuity along the length of the parkway is a defining characteristic of the landscape. The parkway’s history reveals an ambiguity in its purpose between being a scenic parkway and an efficient inter-city highway. That ambiguity has led to repeated attempts to transfer ownership of the route to the State of Maryland, but thus far, those efforts have failed because of the cost of upgrading the roadway to carry commercial traffic. This document argues that part of the B-W Parkway’s historical significance is due to this ambiguity. It shows in its design that it is possible for an ordinary highway to have an aesthetic character consistent with earlier parkways. In the document, the parkway is mapped at a scale of 1:10,000 to show it in regional contexts. Specifically, the maps place the parkway in relation major transportation routes; watersheds, topography and road alignment; the historic national forest proposal; and current forests that are conserved by the adjoining federal properties. These maps show that the parkway plays a distinct role in regional transportation; its layout is influenced by the topography of the watersheds; and that it is an important corridor in the regional forests. The parkway is mapped at a scale of 1:2000 to identify structure and pattern to the design decisions. Topography is an important influence on the alignment and infrastructure of the parkway and even on the age and composition of the adjoining forests. Collectively, these factors distinguish four character areas: the Washington Entrance character area, the Picturesque Urban Parkway character area; the Beltway Transition character area; and the Modern Forested Parkway character area. Of these, the Modern Forested Parkway character area comprises almost two-thirds of the parkway, and its combination of modern road alignment and parkway characteristics is key to the overall historical significance of the design of the B-W Parkway. Maps at a scale of 1:700 document detailed design decisions, especially with regard to safety infrastructure, forest management, and designed plantings. The locations of guard walls and guardrails are shown to be directly related to topography and dangerous traffic conditions, and they are also shown to be consistent in their design along most of the parkway. Later exceptions are documented that detract from this consistency of design. Forests have been disturbed during periods of construction and rehabilitation, and this is evident in patterns of successional and mature forest. Composed plantings have been concentrated at interchanges, where they make a transition between the surrounding suburban landscape and the forested corridor of the parkway. Few of these plantings remain today. A series of sections drawn at half-mile increments documents the spatial sequence of driving the parkway. Spatial conditions can be difficult to record, and these repetitive sections operate like a film storyboard, constructing a facsimile of the driving experience. They reveal that in the most traditional segment of the parkway, the Picturesque Urban Parkway character area, the spatial conditions differ every half-mile. This spatial structure helps inform design decisions especially in places where the spatial conditions do not vary for notably longer distances. This overall analysis informs specific design proposals. New emergency crossovers and pull-offs are located and designed in conjunction to one another to operate as emergency infrastructure (and not be seen as casual pull-offs). They are understated in design in order to continue the character of the landscape. New guard walls are proposed to replace steel guardrails along the main roadway, and consistent guardrails are proposed along interchange ramps where currently there is no consistency to them. Consistency and coherence of these structures is important to the character of the parkway. New mile marker signage is proposed that identifies drivers’ locations in emergencies, and they set a standard for signage along the parkway. A proposal for forest edge management allows for a wider safety margin along the roadway while controlling the spread of invasive plant species. And a method of restoration and rehabilitation of planted vegetation is proposed and applied to key interchanges. These design proposals adhere to a management philosophy consistent with the design and character of the parkway. Part of the historical significance of the parkway is that it shows that a modern highway can indeed have parkway aesthetics. Therefore, it is important that all changes maintain that parkway character and attention to design detail.

Cultural Landscape Report Baltimore Washington Parkway

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