Anatomy of a Historic Road
Every historic road is comprised of three parts: the road, the right-of-way and the setting. Whether an aesthetic, engineered or cultural route, the following features should be surveyed and assessed.
The Road
The road is the physical construction or resource that has been designed or traditionally used for the movement of people and goods. The road is comprised of the following elements:
TRAVELWAY: The travelway refers to the area of the road dedicated to the movement of vehicles. This may also be referred to as a “carriage way” or “travel lane.”
PAVEMENT: Pavement is the durable or semi-durable surface of the travelway. Pavement may be dirt, gravel, wood (plank, corduroy—logs laid side-by-side, or wood blocks), stone (cobblestone or granite Belgian-block), brick, macadam, concrete or asphalt.
ALIGNMENT: Alignment refers to the horizontal or vertical movement of the road. More specifically, horizontal alignment refers to a road’s movement to the left or right—its curves, and vertical alignment refers to a road’s movement up and down—its hills. Horizontal and vertical alignment may overlap, such as a mountain road winding up a steep grade.
SUBSURFACE: Subsurface refers to the stabilized base beneath the pavement. The subsurface provides both a base foundation to support the pavement and a uniform surface on which to lay or adhere the pavement. It is the subsurface that comes in contact with the ground.
CROWN: The crown of a road is a rise or upward arc toward the center of the travelway that provides for drainage. Water is directed to the sides of the road and carried away by a gutter, shoulder or swale.
CURB: A curb is a raised face at the edge of the travelway or gutter. Generally 6-12” in height, a curb provides a physical barrier between the travelway and the adjacent sidewalk or landscape.
GUTTER: A gutter is a channel at the edge of the travelway designed to collect and direct surface or rainwater away from the road. Gutters are generally concrete or brick.
SHOULDER: A shoulder is a stabilized surface that runs parallel to and is flush with the travelway. In general a shoulder is utilized for higher speed roads without a curb and gutter. It varies in width and may or may not be constructed of the same material as the travelway. Shoulders are generally viewed as a safety feature—allowing for a disabled vehicle to move out of the traffic in the travelway.
STRUCTURES: The road may be associated with essential structures that are integral to its design and function. These may include bridges, culverts, tunnels, tollbooths and retaining walls.
The Right-of-Way
The right-of-way includes the road and the adjacent lands parallel to the road, under ownership or easement by the transportation department (or other agency or road owner) and includes the road. In many instances the right-of-way also includes road related features (drainage or signage) or general public services (utilities). The right-of-way may exactly equal the width of the road, or may include an area of sidewalks, street trees or bike paths, or land reserved for future highway construction. Some parkways and scenic roads have extensive rights-of-ways (in cases extending significant distances from the roadway) for the conservation of natural areas or the provision of a buffer from adjacent development. Historic roadside features may be located within or outside the right-of-way. Elements found in the right-of-way include:
SWALE: A swale is a slight depression or ditch parallel to the road that serves as a collector for rainwater runoff.
BARRIER: A barrier is a safety feature designed to protect the vehicle from a hazardous situation. Barriers are commonly constructed as guardrail, walls or posts.
LIGHTING: Lighting refers to both the source of light and its intensity, and the design of the fixture that supports the light source.
SIGNS: Road-related signs provide information for the traveler about road identification (route numbers), location, direction, distance, warnings and regulations. Signs may also provide visitor information, serve as commemorative or gateway features, or provide visitor orientation.
SIDEWALKS: Sidewalks are durable paved surfaces that run generally parallel to the road and are dedicated to the use of pedestrian (and sometimes bicycle) traffic.
PATHS: Paths provide access for pedestrians and bicycles and are generally less formally defined than sidewalks. Paths may originate from an unplanned or organic use (people tend to create paths if no other accommodation is provided), or may have been designed. Paths may be unpaved or have a gravel or asphalt surface.
TREE LAWN: A tree lawn is the area between the curb and sidewalk usually dedicated to the planting of street trees.
STREET TREES: Street trees are trees planted parallel to, and generally in a formal pattern or spacing, to the road.
UTILITIES: Utilities may be above or below ground and include electric, cable, telephone and fiber optic lines; gas, water, irrigation, storm and sewer pipes; and transformers, service boxes and steam tunnels.
STRUCTURES: Structures within the right-of-way may include bridges and aqueducts that carry other roads, railroads or water over the road. They may also include administration buildings (often associated with toll roads and bridges) or inspection structures (border facilities and agricultural inspection stations).
SERVICE AREAS: Service areas may include highway maintenance yards, rest areas or service plazas providing fuel, food and information.
WAYSIDES AND OVERLOOKS: Waysides and overlooks are pull-offs adjacent to the road designed to provide access to a scenic view, interpretation or historical markers, or picnic tables. Such facilities are generally without restroom facilities.
The Setting
The setting refers to the area beyond the right-of-way. The elements comprising the setting are often the features we most associate with a road and use to determine if a drive is pleasant or unpleasant. Elements defining the setting include:
ROADSIDE ARCHITECTURE: Road-related features include structures and spaces that are integral to the design and use of the road. Structures may include gas stations, motor courts, drive-ins, taverns. Seasonal structures may include farm markets, ice cream shops or clam shacks. All may include fanciful architecture designed to capture the attention of the motorist.
STREETSCAPE: A streetscape defines the physical setting and structures along a road in a settled area. A streetscape, whether urban, suburban or rural, is generally associated with a built-up area or concentration of development. Key characteristics of streetscapes are street trees, lights, utility lines, styles of architecture, relationship of structures to the street (adjacent to the street, setback by a wide lawn), public spaces (walks, plazas, village greens and parks) and street furnishings (benches, lights, planters, parking meters, mailboxes).
LANDSCAPE FEATURES: Landscape features include parklands, natural areas and plantings designed in conjunction with or resulting from the creation of the road.
CHARACTER: Character refers to the nature of the landscape or community through which your road passes. It may be rural, suburban or urban in nature. It may be local in character—tidy bungalows with neat lawns—or it may be more regional in character with businesses catering to the needs of the traveler. Character may be reinforced through common or repeating elements that create identifiable, even unique, patterns, colors, and styles along the roadside.
VIEWSHED: Viewshed refers to the “view” from a particular point in space. The viewshed encompasses everything that can be seen by the naked human eye from this point. A viewshed may be very large, such as the view across a valley from a ridge road, or the view stretching across the great plains to the horizon. It may also be very narrow such as the view from a city street, no wider than the sidewalk and terminated by the façade of an adjacent building, or the limited view along a road in a densely wooded area. The viewshed of a road is generally considered the view to the left or right from the centerline of the road.