Uncovering historic pavements reveals each city’s “urban fingerprint.”

By Zach Mortice

In the past 200 years, cities have become larger, safer, and healthier places to live, but there’s one arena of urban infrastructure that has become incalculably more monotonous and denuded: the range and diversity of pavement types on city streets and sidewalks.

Before the dominance of concrete and asphalt, city streets were paved in a wild diversity of minerals and materials: glassy vitrified brick, wooden block, crushed oyster shells, rough-hewn granite blocks, and more.

Robin Williams, the chair of architectural history at the Savannah College of Art and Design, has traveled to 40 cities across North America to study their historic pavements and found a rich spectrum of street coverings that somehow persist with no preservation protections.

His own city, Savannah, Georgia (an architectural historic preservation capital), has six extant types of pavements, with no regulations preserving them or their respective landscapes. “Savannah has a greater concentration and variety of pavements in one landmarked district than any other city,” Williams says.

To ensure that this concentration stays intact, Williams is working with the city to draft a new policy or ordinance to protect Savannah’s historic pavements. “The goal would be to protect all historic street and sidewalk pavements, curbs, and historic street features that are at least 50 years old,” Williams says. It’s early in the process, but civic officials hope to have it in front of the city council by year’s end.

“Through his leadership here locally, [Williams] has not only educated students, but also city staff as far as the importance and significance of the historic materials that are out there on our streets and sidewalks,” says Bridget Lidy, the planning and urban design director for the City of Savannah.

Pavements have a powerful yet overlooked ability to set the context and character of a place. They largely, and literally, form the dominant texture of a neighborhood. And as Lidy says, “We take great pride in preserving those qualities that make us so unique.”

Paved streets and sidewalks began to emerge in the middle 19th century, a leading edge of urban reforms (such as indoor plumbing, sewage systems, and public parks) that began to connect public health with the quality of the urban environment. Using pavement to tamp down the endless dust and mud from dirt streets was seen as an investment more on the scale of major transit improvements such as subways or streetcars rather than prosaic, passive infrastructure.

Early on, paving was a localized and fragmented business. Before the dominance of concrete and asphalt, municipal leaders had to sort through material qualities, shipping costs, the types of traffic each road would incur, and even the soil types present, all yielding different answers for each place. Pavements, as Williams says in a recent TEDx Talk, are an “urban fingerprint unique to that place.” Toronto, for example, had 11 different types of paving at the start of the 20th century, and Savannah has had 13 throughout its history. Heavy industrial uses (such as in the former shipping ports in Lower Manhattan) often used cut granite blocks called Belgian blocks for their strength and durability. A smooth and quiet ride for residential areas called for asphalt, but it was quite expensive, and also readily absorbed waste from beasts of burden on city streets. Bricks did not, but provided a noisy surface as horse hooves clattered over them.

Cobblestones (often brought to American shores as ballast in the hulls of ships) were common among the first efforts to pave streets, but were relatively quickly abandoned for more uniformly shaped materials. Vitrified brick surged in popularity in the late 19th century; withstanding excess heat made it more durable than standard bricks. Asphalt emerged in 1870, and concrete 20 years later, though made with a madcap array of aggregate materials—everything from oyster shells to baseball-size hunks of rock. As these two materials were refined, they crowded out all others, and by the mid-1920s nearly all North American streets were paved.

This progression traces an arc of nearly unimaginable civic uplift that has long since faded into a prosaic detail of the built environment. “We look at them, especially cobblestones, as quaint pretty [things], sort of like looking at a horse and buggy—a time gone by,” Williams says. “I think they should be seen the way you might look at the railroads, and we might look at some other kind of Victorian invention, [an] H. G. Wells-ish thing.” From the early 19th century, “we basically went from a medieval level of living to a paved environment with sewers and water mains,” he says. “I can’t imagine how different those two worlds must have been in the course of a generation. We think of them as quaint, but actually, no, this is hypermodern.”

Protective ordinances for pavements are rare across the country, and the overwhelming lack of regulations means that, often, local bureaucrats have incredible sway over what gets preserved when it’s time to repair potholes. Williams has traveled to places known for their historic infrastructure (Philadelphia, Baltimore, Chicago, etc.) but also to smaller cities such as Lynchburg, Virginia, and Wilmington, North Carolina. (Wilmington has a pavement preservation ordinance.) Before a trip, Williams finds Instagram and Google Street View particularly useful in tracking historic pavements.

The effort to draft an ordinance will get Savannah to grapple with typical preservation quandaries of scope and authenticity (do you protect historic styles of pavements that have been replaced in the recent past?). For example, Williams wants any new rule to preserve both materials and their spatial arrangement, such as Savannah’s triangle-shaped brick patterns at “T” intersections that place bricks perpendicular to wheels as they turn, reducing wear and tear.

Williams has noted ways that idiosyncratically paved streets provide ambient benefits: They calm and slow traffic, and the permeable surfaces they offer can aid stormwater infiltration. Additionally, their varied patterns and textures can communicate nonvisual cues to people with impaired sight.

And these are all values that contemporary cities are waking up to, including the understanding of how impermeable surfaces interrupt and pollute the water cycle and shared streets that elevate roads into pedestrian-friendly, quasi-public plazas. Concrete and asphalt’s dominance coincided with the dominance of the automobile, and their scaleless uniformity suits cars’ velocity, if not the walking pace of people. As lanes of traffic are peeled back for human use, the surfaces and materials needed to complement people’s presence can return to a human scale (a brick, a stone, a wood block) and desire for variability and diversity.

 Zach Mortice is a Chicago-based design journalist who focuses on landscape architecture and architecture. You can follow him on Twitter and Instagram.