“The builders of to-morrow’s roads must be practical dreamers.”
–Victoria Faber Stevenson, American Highways, 1919
Understanding the origin and evolution of a historic road is necessary to evaluate objectively the road resource and identify the need for preservation actions or activities. For some historic roads, exceptional characteristics through design, technology and famous association may have physically, intellectually or culturally affected our regard for the road. For most historic roads, design, construction and evolution over time can be traced to aesthetic, engineered or cultural evolutions.
Defining Historic Roads: Aesthetic, Engineered, Cultural
Skyline Drive, Shenandoah National Park, Virginia. Credit: Paul Daniel Marriott
There are three types of historic roads: aesthetic, engineered and cultural. The determination of road type is based on an analysis of the physical design of the road (a serpentine roadway along a stream, an elevated roadway over an urban area), the goals and expectations through which it was constructed (delivery of mail, access to a mine), its original intended uses (pleasure, commerce, speed), its physical setting (prairie, urban or landscaped park) and the design details that distinguish the road (stone arch bridges, utilitarian concrete culverts, ornate lighting, brick pavement, rough tunnels hewn through rock). For many historic roads, evolution over the years may have refocused or shifted the original goals and aspirations of the road’s creators—leaving a bewildering array of alignments and details. For some, the historic road’s origin may be lost in the wanderings of animals whose traces were eventually adopted by humans or the mundane practicality of two communities wearing a path across the landscape.
Aesthetic Routes
Aesthetic routes represent historic roads designed to provide a very specific traveler experience. In general these historic roads were designed for scenic enjoyment, leisure, recreation or commemoration. Aesthetic routes will have a documented purpose or rationale behind their development and a documented date of construction.
Seldom intended as the fastest or most direct route, aesthetic routes typically follow the natural topography of a region. They may wind through river valleys, along ridge tops, or up rainforest slopes. In urban areas, aesthetic routes are typically represented by boulevards, monumental avenues or parkways. These routes may be lined by great sculptures and ancient rows of trees, anchored by grand public edifices, or trace a serpentine route through public parks and park reservations. Whether crossing the natural landscape or defining a civic landscape, aesthetic routes are distinguished by their thoughtful attention to the traveler’s experience and careful attention to design details. Every view, whether a distant mountain range enframed by trees or a capitol dome rising above the city, is carefully planned and considered in the alignment of the road. Every detail such as plantings, lighting, barriers and pavement is designed or selected to support the overall design concept (the “look” and “feel” desired for the traveler). Often aesthetic routes may influence the larger landscape (beyond the right-of-way) such as a parkway’s viewshed (the views taken in from a particular vantage point) or the building façades along an urban route. Due to their conception and design as a singular statement, any alteration to any component of an aesthetic route will significantly impact the historic integrity of the resource.
Engineered Routes
Engineered routes represent historic roads designed for the efficient movement of people, goods and services. They are our most common designed roadways. While they may exhibit some aesthetic qualities or features, their design intent will be rooted in efficiency of movement, ease of access and prudent construction cost. Like aesthetic routes, engineered routes will have a documented purpose or rationale behind their creation and a documented date of construction.
More pragmatic in their origins than aesthetic routes, engineered routes have been designed to open isolated areas to commerce, reduce traffic congestion, link the nation, or simply link a farm to a market. Engineered routes are unlikely to influence or manage the larger landscape and are usually confined to their defined right-of-way. The alignment and details of an engineered route may be important in the representation of new roadway technologies or material innovations. Early transcontinental highways, turnpikes and toll roads represent many such engineering advances in materials, design and safety. Most basic city grid patterns represent the characteristics of engineered routes. Today, due to location or earlier technologies, many engineered routes have taken on aesthetic qualities as the design and construction techniques of the past become appreciated by new generations of users.
Cultural Routes
Cultural routes represent historic roads that evolved through necessity or tradition. While it is possible some cultural routes may have a documented rationale, they will not have the design and construction legacy of an aesthetic or engineered route. It is possible, and likely, that later additions or alterations may be well-documented—this category, however, addresses the nature of the original origin of the road. These may be roads that evolved from Native American roads, colonial routes or simply logical connections between villages or through difficult terrain. Roads through mountain passes or water gaps, paralleling the foot of mountains or following a line of stable soils or river courses are typical of cultural routes. Additional types of cultural routes may include a footpath between farms or to a resource site (sand, clay, timber or stone) or roads along section lines in the American Heartland (Land Ordinance of 1785) that ultimately became road. Some routes may have cultural associations through use, activity or events.
Cultural routes, in use as roads today, generally exhibit the greatest number of historic periods or layers. Beneath the modern pavement are potentially rich archaeological sites representing not only people and cultures over the years, but also the history of the very route—an ancient, indigenous road running along a stable ridge, areas of compacted soil from fifteenth century European conquest, evidence of a widening to accommodate a carriage in the 1730s, remnants of an old corduroy road from 1790 and early twentieth century highway improvements. For cultural routes, it is important to understand these layers as you make a determination as to the period, or periods, of significance that are worthy of preservation. Remember, subsequent layers of the road may embody the characteristics of aesthetic or engineered routes.
Multi-Category Routes
As soon as a definition is established, there are likely to be exceptions. For the three historic road “types” the question is not so much “exception,” but rather “combination” or “evolution.” Such roads may be defined as multi-category routes. Every road will be able to be categorized as aesthetic, engineered or cultural. As noted, many cultural routes may have aesthetic or engineered alterations over the years. Some may represent the characteristics of two or three of the defined categories at the point of design and construction. Such historic roads may be early freeways (engineered) that were also designed to provide a scenic experience within a spectacular natural setting (aesthetic). Others may be parkways (aesthetic) that were also designed to provide quick efficient movement for metropolitan commuter traffic (engineered). Usually, but not always, one of the three categories will be recognized as the primary characteristic-defining origin of the road.
Multi-category routes may be represented by roads with origins as a Native American road (cultural) that were adopted by European settlers for their trade needs (engineered) and ultimately redesigned as a parkway (aesthetic)—the Natchez Trace Parkway in Tennessee, Alabama and Mississippi, for example. A city grid pattern, as a whole, may be viewed as characteristic of the engineered routes category, but may include a grand avenue clearly characteristic of the aesthetic category.
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.
Colonial Parkway, constructed 1930–1957, Colonial National Historical Park, Virginia. Credit: Paul Daniel Marriott
Identifying the Current Status of a Historic Road
Few historic roads exist unchanged and unaltered since first traveled, conceived or constructed. Many historic roads are characterized by evolution and change that present the modern observer with an array of layers, alignments, materials, alterations, accommodations, and even losses over the years. When identifying a historic road, it is also important to investigate the current status of the road. Only with a complete understanding of the road’s history and its current status can a comprehensive plan of action (preservation, restoration, interpretation, advocacy) be undertaken.
Losses, Threats and Destruction
Many historic roads face severe losses, threats and destruction. Someone or some policy determines that a historic road should be widened or straightened, the cast-iron lights are a safety hazard or stone curbing is to be replaced with concrete. Often such actions are undertaken without an understanding or appreciation for the road as an historic resource—the action often a part of standard transportation practices and policies.
When identifying negative impacts to an historic road, it is important to understand the origin behind the activity. Safety is the reason most often cited to justify an action on a historic road. Other common issues are congestion, maintenance (a new material or detail is easier or less expensive to maintain or repair; or a historic replacement part is no longer available) and expense. Most threats to historic roads fall within four categories: realignment, replacement, demolition and regional or outside pressures.
Realignment: Realignment refers to the adjustment or movement of the horizontal or vertical alignment of the historic road. Realignment is cited when the proposed shift represents only a portion of the historic road—the activity reconnecting to the historic alignment at some point. Realignment may be as simple as a shift in the travel lanes to soften a sharp curve, or as destructive as several miles of new road abandoning the original alignment.
Replacement: The replacement of road and roadside features can greatly alter the context and integrity of a historic road. A historic road is a collection of details—cobble gutters, concrete paving, art deco lighting, limestone bridges, park lawns, woodlands, sandstone outcroppings and Beaux Arts balustrades. It is likely that time, wear or even accidents may necessitate the replacement of an element or elements of a historic road. Every effort should be made to replace the elements with like materials, constructions, finishes and forms in their original location. While the improvement of such features with modern technologies (such as reinforcing guardrail or providing a break-away mechanism for lighting or signs) may be considered for safety or maintenance, the replacement of historic materials with imitation products or false finishes, is an example of incremental destruction and should be carefully considered and likely avoided.
Destruction: Destruction refers to the complete removal of a historic roadway or roadside element. There are two types of destruction—complete and incremental. The loss of an entire historic road, through a single action, is an example of complete destruction. It is possible that the same destruction could occur incrementally over a period of years, even decades, through cumulative losses, realignments, replacements and other activities that, combined, ultimately result in a complete destruction. Incremental destruction can occur through a systematic policy or program to replace the historic road, or through a series of seemingly unrelated events and policies.
regional threats: Regional threats address the broader landscape and region in which your historic road is located. Are changes in the area, seemingly unrelated, having an adverse effect on your historic road? New development, the extension of sewer and water lines, or shifts in tourism may suddenly increase the traffic volume on your historic road—altering driver behavior, speed and safety. Does the change contradict the design origins and purpose for which the road was designed—a parkway becoming a commuter route or a farm-to-market road transformed into a commercial strip? Of all the types of threats, regional threats are the most difficult to control. Still by being cognizant of, and anticipating such possibilities, you can work to minimize negative impacts through advance planning or policy.
Safety, Liability and Resiliency
Safety, liability and resiliency concerns drive many of the actions, activities and management decisions for all roads in the United States. The federal, tribal, state or local government that owns the road not only has a public duty to make the road as safe as possible, but also carries the legal responsibility (liability) for maintaining a safe road and, increasingly, is making decisions based on anticipated infrastructure needs for climate change.
Safety goals and expectations continue to change and evolve with technology and driver behavior. With few exceptions, historic roads, regardless of an illustrious past, must meet many of the expectations and obligations of the modern highway network. While a historic road may have been a safety innovator and model fifty years ago, it is likely that new safety regulations, liability and resiliency concerns will govern its management today. There exist, however, innovative safety options and strategies that can enhance a historic road’s safety while also respecting preservation goals. Some solutions may be simple—the redesign of a cast iron lamp post in a light-weight steel that offers a break-away feature should it be struck by an errant automobile. Others may be more involved (and expensive), such as the placement of a concrete core inside a historic stone wall to meet modern crash standards. Still others may involve cutting edge technology and creativity such as intelligent transportation systems, speed management or traffic calming. It is essential to assess the current safety, liability and resiliency status of a historic road in order to advocate for or implement alternate methods and solutions more appropriate for a historic road. When identifying issues of safety and liability concerning a historic road, it is helpful to identify the following:
managing agency: Almost every road in the United States is owned and managed by the federal, tribal, state or local government. In a few rare instances a road may be privately owned and managed. Ownership impacts virtually every decision from physical features, funding and maintenance, to the ethic a particular organization may have toward historic preservation. The managing agency (often a state or tribal transportation department, or local department of public works) will have information on future plans and activities for roads under their jurisdiction.
functional classification: All roads in the United States are identified by a “functional classification” characterizing the road’s use. Functional classification is the basis from which most management decisions, design requirements and safety policies arise. Functional classifications are: freeway, arterial, collector and local.
land use: Land use planning policy (zoning, master plans, comprehensive plans), perhaps seemingly unrelated, can have a significant impact on historic roads. Plans that allow for or encourage suburban sprawl can put unexpected pressures on historic roads as populations grow and transportation patterns adjust to new destinations. Conversely, plans that encourage agricultural preservation or smart growth may, by default, preserve the character of historic roads by working to maintain a service level that allows the road to continue functioning safely.
resiliency and climate change: Specific regional concerns such as avalanche, frost heave, flood, hurricane, tsunami or earthquake may place special burdens on historic roads not considered originally and exacerbated by climate change. Historic bridges and culverts, considered safe by modern safety and engineering standards, may not offer sufficient clearance or capacity for high volume storms. Increasing wind or ice events may threaten historic trees now identified as hazards, and historic views along tidal waterways may be compromised by the construction of new storm barriers. As the managers of historic roads assess the resource and prepare plans to accommodate climate change, make sure historic features, materials and landscape relationships are proactively considered and addressed as a part of the planning strategy.
liability laws: Liability concerns are based in safety considerations, but are the direct result of public policy and law. What is the risk the road owner (managing agency) carries? Will the state, tribal or local government managing a historic road carry a burdensome risk, or be accused of negligence should an accident, injury or fatality occur along the road? Every locale’s laws vary.
Lincoln Highway, Nevada.