El patrimonio cultural de la obra pública 3 | Paul Daniel Marriott
Researcher, consultant and promoter of the forum Preserving the Historic Road
“The road remains the single most resilient heritage resource across all cultures and places”
Paul Daniel Marriott is one of the most influential international voices in the conservation and management of historic roads. His career, spanning more than three decades, has helped consolidate the discipline of historic road preservation as a specialized field at the intersection of engineering, landscape architecture, territorial planning, and cultural history. From the United States, his work as a researcher, consultant, and, especially, as the driving force behind the forum Preserving the Historic Road, has created a unique space for dialogue among public agencies, design and engineering professionals, scholars, and citizens interested in the cultural value of roads.
Through his work, Dr. Marriott has promoted an integrated understanding of historic roads as living infrastructures that connect territories, memories, and communities, and that require planning approaches sensitive to their cultural and landscape character. His experience in developing guidelines, conservation strategies, and methodological frameworks has had a decisive impact on the way these routes are identified, assessed, and managed across many contexts. For countries such as Spain —where historic routes, scenic regional roads, and national itineraries with strong cultural significance coexist— his insights are particularly relevant.
This interview aims to explore his views on how to define, preserve, and envision the future of historic roads, as well as the lessons learned throughout decades of work in a field that today seeks greater institutional and public recognition.
Rita Ruiz Fernández
The definition of a “historic road” often varies across countries and cultural traditions. In your work, you have articulated a vision that integrates engineering, design, landscape, and territorial memory. What essential criteria do you consider necessary for recognizing when a road or route should be understood as cultural heritage?
Roads are one of the most indelible lines inscribed across the surface of our planet. The movements of past peoples may be traced along these ways, and their cultures and ingenuity may be measured by the alignments they identified or constructed for travel. To fully consider their significance as historic routes, we must evaluate their engineering, design, landscape, and culture as integrated resources and ideas. A road without context is illegible.
When I began my career in heritage, roads were not considered historic resources. Prominent preservation leaders in the United States told me that roads did not meet the criteria for the National Register for Historic Places; an ICOMOS committee opined that automobile roads could not be eligible for World Heritage.
My advocacy and research for historic roads began with the Bronx River Parkway in Westchester County, New York. Designed and constructed as the first automobile parkway in the world (1906-1925), the Bronx River Parkway was a specific type of roadway constructed for pleasure driving. Parkways, with design origins from the late eighteenth century, are roads closely aligned with the natural topography and organized to showcase the beauty of the landscape. My initial study of the Bronx River Parkway, prompted by the planned demolition of a historic bridge, not only identified questions about its design history, but also the safety and function of the parkway as part of an active transportation network.
For historic roads, such as the Bronx River Parkway, I identified a serious conflict between the historic design and current expectations for highway safety and function. To begin, I read the manual, A Policy on Geometric Design for Highways and Streets, published by the American Association of State Highway and Transportation Officials (AASHTO) to understand how engineers viewed historic roads. Unlike a heritage building, for which accommodations for modern safety are thoughtfully accommodated with alternative solutions, there was no similar protocol for historic roads. However, before alternative safety solutions could be considered, I realized a method to identify and categorize historic roads was required.
In Saving Historic Roads (New York: Wiley, 1998), I established three classifications of historic roads: aesthetic, engineered and cultural. The purpose was to inform heritage decisions with standard definitions based on the initial intent for the road. The determination of road type was based on an analysis of the goals and expectations from which it originated or for which it was planned and constructed, and the design details and landscape context that distinguished the built road. Within each classification, I identified the need to understand the road, the road right-of-way, and the context. These classifications are now used by the US National Park Service and numerous state and local governments. They allow a wholistic approach to evaluate a route for significance and integrity, and identify the best practices for conservation, preservation, and management
Aesthetic Routes
Aesthetic routes represent historic roads for which the primary rationale for development was the creation of a specific visitor experience in a moving vehicle. Aesthetic routes such as parkways and park roads are designed for the purpose of leisure, recreation, and commemoration. They have a documented origin and construction date. Never intended as the fastest or quickest route, such roads typically follow the natural topography of the region and are most often associated with a designed landscape or park space. In urban areas, park boulevards and monumental avenues exhibit an equally high level of detail and composition. Aesthetic routes prioritize the alignment and context to define the travel experience.
Engineered Routes
Engineered routes represent historic roads designed for the efficient movement of people, goods, and services. They represent 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 rationale behind their origin and a documented date of construction. Such roads may influence or manage the larger landscape due to their location, but their design intention is limited to the associated right–of–way. The alignment and details of an engineered route may be important in the representation of new roadway technologies or material innovations.
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, such as colonial roads developed under the Laws of the Indies, they may not have the site-specific design, geographic location and construction legacy of an aesthetic or engineered route. While it is possible that later additions or alterations may be well–documented as aesthetic or engineered modifications, this category addresses the origin of the road. Cultural routes in use as roads today, generally exhibit the greatest number of historic periods. Some with multiple or parallel alignments may represent multiple categories.
Contemporary mobility places technical demands that often come into tension with heritage preservation. Public agencies and designers must balance safety, capacity, regulations, and cultural protection.What would you say are the most frequent challenges in managing historic roads, and what strategies help reconcile mobility needs with the conservation of their character and authenticity?
The first challenge, certainly in the US, is the recognition that a road can be historic. While the historic roads movement has significantly raised awareness for these resources, many transportation agencies continue having difficulty viewing a segment of a contemporary transportation network as historic. Roads, such as the Bronx River Parkway and the Arroyo Seco Parkway in Los Angeles (1940), once celebrated for their advanced safety features, are criticized for not meeting current highway design guidance. Frustrated transportation engineers blame outdated highway design while trying to force higher speeds and traffic volumes onto the historic roads designed for fewer automobiles and speeds of forty to eighty km/h.
In addition to ignorance of the resource, some transportation agencies argue that the road must meet currently held safety protocols. However, in the United States, the Federal Highway Administration (FHWA) and AASHTO offer flexible alternatives for transportation agencies to improve safety on historic roads. In addition, new global strategies for traffic calming, road diets, complete streets, and context sensitive solutions, have enhanced opportunities for historic roads. As a result, I have learned that arguing safety, over heritage, is very effective. Rather than looking at a historic road as a problem, consider how the historic design may offer contemporary safety benefits. For example, a narrow bridge or stone surface may support traffic calming; maintaining the road at the speed for which it was designed may improve automobile safety while also enhancing multi-model use.
I find that transportation agencies that employ or partner with landscape architects, archaeologists and heritage professionals are more successful identifying flexible solutions for safe historic roads. For example, a beautiful curve on the Bronx River Parkway was causing accidents as speeds increased. The county transportation agency insisted the curve be straightened for safety. I noted that the curve, designed in the 1920s, did not have superelevation. With pressure from a local legislator, the county superelevated the curve. This preserved the historic alignment of the parkway and improved safety, at a much lower cost.
Some states are more proactive in protecting their historic roads. The Historic Columbia Highway in Oregon (1916), based on the nineteenth-century Axenstrasse in Switzerland, is a National Historic Landmark, —the highest heritage designation in the United States. The Oregon Department of Transportation developed model programs to manage historic roads and hired transportation historians. When I was working with a historic parkway in Boston, the engineers from the Massachusetts Department of Conservation and Recreation proposed changes for an intersection to improve efficiency that did not meet the highest engineering level of recommended service. When I questioned why they recommended a lower level of service, I was told that any additional increase in automobile efficiency would lower efficiency for pedestrian and bicycle users.
Oregon and Massachusetts demonstrate that improved education and strong partnerships can protect historic roads and help meet state goals for multi-modal access and sustainability.
The Preserving the Historic Road program has, for decades, generated a shared space for reflection among engineers, designers, historians, heritage managers, and public administrations.What contributions would you highlight from this collective work, and what lessons do you believe might be useful for countries like Spain, with such a historically layered and diverse road network?
In 1994, after my early research on the Bronx River Parkway, I wrote an article for, CRM Journal of the National Park Service, “Historic Parkway Design: A Look at the AASHTO Green Book.” The text outlined strategies to balance safety and engineering needs with conservation. In 1995, I co-hosted a conference on the Bronx River Parkway with the Historic American Engineering Record (HAER) of the National Park Service to address heritage, conservation, and safety needs for parkways. Soon I was being contacted by advocates and transportation agencies regarding conservation for other types of roadways, including eighteenth-century turnpikes, rural concrete roads from the early twentieth century and US Route 66.
These early conversations prompted the idea for a national conversation about historic roads. In 1998, in partnership with the HAER, the US National Trust for Historic Preservation, and the California Department of Transportation (CALTRANS), the Preserving the Historic Road conference was established. The conference was hosted in Los Angeles with the historic Arroyo Seco Parkway (Pasadena Freeway) as the focus. Due to my early work with parkways in the Northeast, we believed it was important to focus on the Pacific Coast and America’s first freeway to establish heritage roads as a nationwide resource at risk.
Education and awareness for the significance of historic roads, as well as respect for their safe function, were at the center of our conversations from the beginning of Preserving the Historic Road. To reinforce this goal, the conference was only held in a state where both the state historic preservation office and the state transportation department agreed to jointly sponsor the conference. In addition, AASHTO agreed to serve as a conference sponsor. As the nationwide representative for state and tribal transportation departments, AASHTO’s involvement gave credibility to the nascent historic roads movement.
The conference was respected by both the heritage and engineering communities as balanced and objective. In addition to showcasing new heritage methods to document the Santa Fe Trail and Route 66 in New Mexico, the National Transportation Safety Board shared best practices to assess safety features on America’s public roads. Lawyers discussed liability laws for engineers in different states. The New Jersey state preservation office and transportation department presented a joint plan for the first statewide historic roads inventory. We offered breakout sessions addressing salt corrosion on historic bridges, Black travel guides during segregation, and the redesign of historic safety barriers to meet modern standards. Most importantly, we welcomed conflicting and controversial opinions during our general sessions and had thirty minute breaks between sessions for participants to discuss and debate historic roads.
Representatives from Mexico attended the first conference, followed by several nations in the early years. Early participation from the French led to heritage road conferences in France and offered new perspectives for the conference. In 2004, at the suggestion of Australian speaker, we changed the name of the conference from Preserving the Historic Road in America to Preserving the Historic Road International. We welcomed our first participant from Spain in 2012.
In 2004 I had the privilege of presenting my historic roads research at an ICOMOS conference in Madrid. Since then, I have had the privilege of communicating with a number of Spanish academics regarding the heritage road legacies our two nations share. For nations such as Spain, with historically layered roads and globally recognized pilgrimage routes, I hope Preserving the Historic Road can provide a framework to further recognize Spain’s significant transportation and engineering legacy. Importantly, I hope that Spain will offer us new insights and perspectives as we continue this important global conversation.
In recent years, historic infrastructures and cultural landscapes have gained visibility in public debate. Because of their ongoing functional role, historic roads face both opportunities and threats.What communication, outreach, or public engagement mechanisms do you consider most effective in raising awareness of the cultural value of historic roads and routes?
Until historic roads are fully recognized as significant heritage resources, I believe we need strong advocacy at all levels to build awareness. Beginning with established protocols to identify and evaluate heritage resources, we need to make sure that historic roads are fully documented as individual resources of merit or contributing resources of significance. For heritage documentation, we must commit to engineering and material inventories that are as rigorous as we would expect for a historic building. We need to develop programs for communities to understand the legacy of their road and support those programs with research from academic programs dedicated to historic roads. For roads that are currently recognized under local, national or World Heritage designations, we need to review earlier nominations to assess the quality of the documentation for engineering, construction and technology, and update nominations if necessary. Lastly, we must inventory the larger designed, natural, and cultural landscapes that make every historic road legible.
Many historic roads traverse cultural landscapes that were designed in harmony with the road or represent the historic context of the region. Despite increased visibility for cultural landscapes, I still find many communities prioritize architecture over landscape— saving a historic gas station along Route 66 or a posada along El Camino Real de Tierra Adentro. It is the often the relationship of the highway to the cultural landscape, more than the relationship of architecture to the highway, that defines a historic route.
To conclude on a more personal note: after decades dedicated to the recognition and protection of historic roads, what continues to motivate you in this work, and what legacy would you most like to leave in this field?
When I began my research in the early 1990s, I anticipated historic roads would be recognized global resources within a decade. That did not happen. What did happen was a conversation that became a movement, and a movement that became global. I am not sure when it happened but, for me, the journey was along the Hana Road in Hawai’i, The Great Ocean Road in Australia, El Camino Real de Tierra Adentro in Mexico and ancient pilgrimage routes in Japan. I traveled most of Route 66 and stood on the last unpaved section of the Alaska Highway in Canada. I walked eighteenth-century pleasure drives in England design by Humphry Repton and followed Thomas Telford’s roads in the Highlands of Scotland. I have partnered with World Heritage, the National Park Service and FHWA, and archives, historic trusts, conservancies and advocates from Paris and Madrid to Santa Fe and Woodstock, Vermont. Every engagement and every community was defined by a road from the past.
Across history, many modes of transportation have transformed our travel and communication. Yet for all the innovations, the road, the line that connects two points on the landscape, remains the single most resilient heritage resource across all cultures and places.
While I am honored that my work with historic roads has inspired a global conversation, I am most grateful for institutions, such as yours, that are advancing practical and intellectual inquiries to further the recognition and conservation of these important resources. The publication of Revista de Obras Públicas issue about the heritage of roads will be the first time an engineering journal has highlighted historic roads. Not only will this enhance the stature of Spain’s historic and cultural routes, but it will also establish professional engineers as stewards of Spain’s distinguished engineering and transportation legacy across the centuries. From the Camino de Santiago to Despeñaperros or Contreras road this journal will establish a new awareness for historic roads in Spain.
A road, without context is illegible.