The Philly Suburbs Are Bigger Than Ever — Literally

The Philly suburbs keep expanding. / Illustration by Jamie Leary

To get from Philadelphia to Allentown, you have two highways to choose from: the Pennsylvania Turnpike Northeast Extension or Route 309.

Anne Mosher is familiar with both. She’s an associate professor of geography and the environment at Syracuse University, and even though she lives in New York, she has close ties to this area: Her late husband grew up in Philly’s northern suburbs, in Hatfield and Lansdale. She has devoted her career to urban historical geography — how cities and their environs have evolved and competed for influence and resources over time. So she’s keenly interested in how the relationship between the Delaware and Lehigh valleys has changed over the years.

She and her husband got to see the change firsthand on a 2019 trip to Schuylkill County from Philadelphia. They’d ordinarily take the Northeast Extension, but because it was closed, her husband had to drive up 309 instead. And he was astonished at what he saw along the highway.

“He said, ‘God, I can remember when this was just all cow fields, and now it’s little McMansions,’” Mosher recalls.

The change may not appear so dramatic to those who live in this region, but over the past decade or so, it’s gotten to the point where when you drive up 309, it’s impossible to tell when you’ve left the Philadelphia orbit and entered Allentown’s. And that’s not the only change. Philadelphia’s urban fringe has been steadily growing toward Reading and Lancaster over the past 20 years or so. In that time span, the buffer between our suburbs and those of Wilmington has been completely erased. And it’s no secret that the New York and Philadelphia regions now meet and overlap along the Delaware River, not only in the Trenton area but increasingly in parts of Bucks County, too.

What were once distinct and separate cities and regions have grown into one another, and they now compete for land, businesses, houses and loyalties in a way they didn’t before. The same processes­ that turned the Northeast Corridor into America’s first megalopolis are also at work in Philadelphia itself, changing it into a metropolis that might be absorbing its neighbors.

Much as the universe has been expanding in the wake of the Big Bang, Philadelphia has been spreading ever since Thomas Holme laid out the original town for William Penn in 1682. And for just as long, says Mosher, cities have been staking claims on the countryside beyond them as places where they can grow — and as places whose trade and production they can capture.

In the 18th century, it was the need for agricultural products that drove metropolitan expansion. William Penn, for instance, gave settlers in his town “liberty lands” outside its boundaries where they could establish farms. Those farmsteads eventually became Northern Liberties, one of Philadelphia’s first suburbs.

Even then, nascent cities flung tentacles far into the wilderness to capture more goods. “Cities like Philadelphia, New York, Boston and Baltimore all raced to control the flow of resources from these outlying areas into their city through the construction of canals, railroad lines and highways, and then by establishing corresponding banking, communications and manufacturing networks that, again, all flowed back to their city,” says Mosher.

This set up competition between cities as far back as the 18th century. Benjamin Franklin famously remarked that New Jersey was “a keg tapped at both ends” by the cities just over its borders — New York in the north and Philadelphia in the south. But as some cities grew bigger than others, their metropolitan expansion eventually swallowed up smaller nearby centers. Newark is a satellite of New York because it was so close to Manhattan, and Wilmington has become one of Philadelphia because of their proximity and transportation links.

Today, what drives metropolitan expansion and rivalry isn’t the desire for the bounty of the hinterlands, but rather business and population growth. In the beginning, the growth of a city’s economy led more people to move there, and some of them took up residence outside its borders. Trains, and later streetcars, took those folks to their jobs in the city, and thus suburbia as we now know it was born. In more recent times, the rise of “edge cities” like King of Prussia has led to further expansion as those places develop commuter sheds (think watershed, but for workers) of their own. (For instance, it’s just as easy for someone who works in, say, Exton to live in Adamstown in Lancaster County as to live in West Philly.)

Much of what drives this expansion, says Mosher, is business economics. Companies tend to locate back-office operations, data centers, and distribution facilities, for instance, in places where land costs less. In the case of distribution centers, access to interstate highways is also crucial. Those factors, along with the rise of e-commerce, explain why the Lehigh Valley is now studded with distribution and logistics operations. And the pandemic-driven shift to working from home has untethered many office workers and other professionals from the need to live close to their worksites.

But even before the rise of telecommuting, metropolitan expansion was redrawing regional boundaries. Jason Duckworth, president of Arcadia Land Company, noticed that as he worked on developments in lower and central Bucks County in the 1990s.

“Back in the 1990s, the greater Princeton job market began to encroach on Lower Makefield, Upper Makefield, Yardley, Newtown,” he says. Pre-COVID, he notes, “More people commuted to Central Jersey than to Philadelphia.

“Historically, [SEPTA] Regional Rail tied all these places together,” he continues. “These places were within the orbit of Philadelphia. But by the 1990s, the job growth was really coming up to their north. There were even people commuting by train to New York City. And that’s why you have 9/11 memorials in lower Bucks County — because there were in fact people in lower Bucks who were in the Twin Towers that day.”

Peter Rotelle, CEO of Rotelle Development Company, builds custom houses in one of those areas where Philadelphia is growing toward another city: Chester County, which borders Lancaster County. He likens the process to mushrooms.

“As each mushroom grows, they start to overlap and connect,” he says. “If you put a dime on top of Lancaster, Philadelphia and Allentown on a map and then, five years later, you put a quarter around them and draw a circle around that and then another five years goes by, you put a half-dollar on top of them, soon, those circles are going to overlap.”

Philadelphia suburban growth, mapped. Learn more about these towns in our guide.

Developers like Rotelle and the people who buy new homes from him are pushing those rings further outward. Those expanding, overlapping circles then produce changes, contrasts and sometimes conflicts of their own. One of the major points of conflict comes over saving open space and preserving what remains of an area’s rural character. Kelly McGowan, a partner in the Doylestown office of law firm Obermayer, Rebmann, Maxwell & Hippel LLP, says this has been a longtime concern in Bucks, stretching back to the 1980s and even earlier.

“Then and now, Bucks County has had a focus on its rural character,” says McGowan. “And you see it in local ordinances reflecting that — agricultural preservation zoning districts and cluster development options that allow developers to build while maintaining significant amounts of open space, for example.”

Such ordinances, however, have perhaps unintended side effects: They push development further out and make what gets built more expensive.

“My dad, Joe Duckworth, built several thousand homes in the ’80s and ’90s in this area of lower Bucks County,” says Jason Duckworth. His current project, a 60-unit development in Newtown Township called Mayfield, contains all the new homes currently being built in the highly regarded Council Rock School District. It took Arcadia eight years to hammer out details of the development, working with community residents.

The result is a walkable community of 60 homes clustered around a town green. Duckworth happens to prefer this more traditional style of development, so both he and the surrounding community are pleased with the final product.

What doesn’t please him is how much more the homes cost than they did when his father was building in the area. “I remember my dad doing houses in the low $100,000 range,” he says. “And my project, when we started it, I thought the houses would sell for about $500,000. They’re selling for $1.1 million. On the one hand, it’s a great thing for me as a businessman. But as someone who has a concern about the region, it’s a travesty.”

Duckworth was happy with the outcome at Mayfield, but he says the residents were perhaps overly concerned with saving open space. “We were right next to a limited-access highway, the Newtown Bypass. It was not a bucolic site. But development concerns feed into opposition, and it just ends up taking a lot of time.” And time is money.

Duckworth’s experience serves to underscore one of the points McGowan makes about real estate development: As former House Speaker Tip O’Neill said about politics, all development is local. There may be concerns that affect entire regions, such as housing affordability or saving the countryside, but when the time comes to put shovels in the ground, all that matters are the laws and conditions in the community where a developer wants to build.

“Land development tends to be a collaborative process,” McGowan says. Her firm specializes in working with developers on legal issues affecting their projects, so she has more than a little familiarity with the subject. “I think any of our clients should have an understanding of not only the region, but also the locality they’re going into and the needs and desires of that particular municipality.”

And those needs and desires can vary greatly, not only across a region but within a given part of it. “It’s difficult to generalize what issues are important to everyone,” McGowan notes. “You might find a place where economics are more important, or one where land preservation is more important than sustainable development. It all depends on the needs and focus of that particular municipality.”

Still, people have to live somewhere. And one municipality’s concern with saving its rural character will likely translate into another becoming a locus of construction it may not have wanted. “Development pressures on municipalities in Bucks County have been here for some time,” says McGowan. And individual communities will continue to focus on keeping the things they perceive as making them unique. “That’s where the collaborative process comes in. Understanding these municipalities doesn’t mean there’s not a way for developers and property owners to work together with municipalities for quality development.”

Local efforts to preserve a community’s distinctive features serve as ways to preserve its identity in the face of change. Because there are so many communities hereabouts, the result is a patchwork quilt of identities and concerns. And as new residents come in from elsewhere, those identities can change, as Duckworth noted in Bucks County. Rotelle, however, sees the multiplicity of local identities and the changes as positives. “Neighborhoods may have changed because the neighborhood changed, and that’s just the way life has gone,” he says. “But what I think has happened is pretty cool where these different vibes and lifestyles and communities have been created.”

Some of the communities that change may help other nearby areas stay more the same. Take Ambler in Montgomery County, for instance. When Rotelle’s family lived in and near it, “Ambler was just a sleepy kind of town,” he says. “And you had suburban sprawl already surrounding it. But that town is now hip. It’s cool. It’s created its own identity over the last 15 years. It’s really transformed well and made an improvement to the suburbs.”

Ambler, of course, sits along a railroad line, which means it had a walkable nucleus around which to build that new identity. Modern highways like Route 309 in Montgomery County and Route 100 in Chester County don’t lend themselves to that kind of community-forming. Instead, they become “linear cities” of sorts, lined with development from one community to the next. That, however, may have helped save some of our region’s countryside, too.

“If I turn off Pottstown Pike” — Route 100 — “there’s tons of farmland,” says Rotelle. Mosher says much the same thing about the northern Philly suburbs where they bump up against the Lehigh Valley. “This year, we went down for a Phillies game,” she says, “and we had to take the back roads because of a road closure. And I was astounded at just how far back in time everything appeared. It was what I think 309 must have been 25, 30 years ago, when there was space in between small hamlets and it was mostly farming.”

From a cultural perspective, this blurring of the lines between cities and their hinterlands may not lead to a loss of local or regional identity. It may not be possible to tell when you’ve left Greater Philly and entered the Lehigh Valley just by looking at the buildings, but stop into one of those buildings, strike up a conversation, and you may still be able to tell the difference.

Mosher says this sort of blending is happening throughout the Northeast megalopolis. “What all of this adds up to is a really complicated rewiring of activity patterns where people who live in the hinterland have greater choice as to which big city they gravitate toward for employment/shopping/sports-team fandom, where they can more easily travel to the big city they find most appealing, thus making areas around places like Allentown, Carlisle, York and Scranton into urban-rivalry free-for-alls,” she says in an email.

So are our neighbors in danger of losing their identity to an even greater Greater Philadelphia? It appears not. After all, way back in the 1830s, opponents of a proposed railroad that would run through the city via Broad Street urged citizens to fight the line lest they “consent to become a suburb of New York.” That railroad did get deep-sixed, but others emanating from here created Philly’s own suburbs — and, yes, made getting to New York easier.

Those New Yorkers are settling not only in Bucks County but elsewhere in the suburbs as well as in the city itself. They’re moving for the same reason some of their employers moved their back offices out of the city to some highway interchange in Pennsylvania: It’s cheaper here.

And even though some Philadelphians (and Allentowners) grumble about those New Yorkers’ presence, most of them have managed to fit in with us locals. That won’t change as people working in Exton buy houses in Lancaster County because they can drive to their jobs more easily and get more house for less, or when someone in upper Bucks County opts to move to a house in a community whose ZIP code begins with 180. Even as suburban Philadelphia overruns the Lehigh Valley and annexes Pennsylvania Dutch country, those places will remain recognizably themselves, just as Wilmington does today. All you need to do to find them is get off the highway and onto the back roads.

Published as “Our Ever-Expanding Suburbs” in the March 2023 issue of Philadelphia magazine.