Not a fork in the road as much as a spoon.

While it’s easy to derisively brand American suburbia as homogenous and essentially unchanging since it emerged as the preferred settlement pattern for the majority of Americans fifty years ago, we hardly need an intense study to see how much they’ve evolved since the postwar housing boom that began in the late 1940s.  In fact, this “study” glosses over it about as superficially as you can.  But it gets the point across, and it provides the backdrop for an interesting glimpse at what innovations (if that’s the right word) we typically see today.

Go back in history and take a look at the street pattern from subdivisions that sprouted across the purlieus of major metros in the 1950s and early 1960s—about the same time that the Federal Aid Highway Act of 1956 galvanized construction of limited-access expressways through the hearts of medium and large American cities.  By the time President Eisenhower authorized the Federal Interstate Highway System, this segment of Levittown, PA (outside Philadelphia) had already enjoyed several consecutive years of astronomical growth:


By today’s standards, Levittown’s homes are modestly sized, the lots small enough to force the homes close together, and the garages/driveways barely accommodate two cars.

But they still represent a remarkable achievement in enabling homeownership to an emergent middle-class that had never enjoyed such a luxury in the past, particularly when the crippling Great Depression brought virtually all housing construction (and ensuing growth in independent households) to a screeching halt.  Average people could afford these homes.

Now let’s do the time warp again thirty years more, by veering about 10 miles closer to central Philly.  Witness the change in the layout of the streets:

While everything contained in this Google Map rests within the municipal boundaries of Philadelphia (unlike anything from the previous Levittown map), the most appropriate description of the neighborhoods outlined here is “transitional”.  The street configurations to the west of the large, bisecting Pennypack Creek Park still mostly abide by the conventional street grid that Philadelphia and most American cities used as the basis for neighborhood design until around World War II.  However, the east side of Pennypack begins to display a mix of conventional grids along with the same carefully ordered curvilinear streets that dominate Levittown further to the north.  Housing developers after World War II, at the onset of the baby boom, began experimenting with street designs that boldly defied the four-way stop and quadrilateral.  These new subdivisions meandered and undulated, continuing uninterrupted without any intersections for much longer intervals than any grid would allow.  The William Levitts of the era gambled by speculating that Middle America would buy into sinuous streets that, though potentially more confusing and less suitable for navigation, helped break the visual monotony of a street that stretched to the horizon line.  Curvilinear streets seemed to work well in the prestigious pioneering streetcar suburbs designed by Frederick Law Olmsted, such as Riverside, Illinois (outside Chicago) or Shaker Heights, Ohio (outside Cleveland).  Why not export this typology to the middle classes?

The gamble paid off in spades, and first-time homeowners embraced the street design that all three of the major Levittowns employed.  Before long, virtually every major metro witnessed the development of communities that followed the Levittown model, with most proliferating at about the same time that the central cities endured the cataclysm of interstate highway construction right through the central neighborhoods.  Thus, it should come as no surprise that these 1950s suburbs nearly always stretch in close proximity to either their city’s major interstate highway, the circular beltways (with three-digit numbers instead of two) or both.

But this elegantly winding braid of streets still generally lacks something we associate with today’s suburbia: complete automobile dependency.  It might not be easy or particularly desirable, but usually Levittowns are still tightly organized enough that it is possible to walk to a few destinations.  Purely hierarchical street patterns—in which one “trunk” road provides access to “branches” and then still smaller sprouts—did not catch on until later, meaning we have to go back to the future (and much, much further out from the city center) to see the sort of development patterns that emerged in the late 1960s and 70s.  The map of upper Bucks County (north of Levittown) proves this.

By the time the overwhelming majority of households had at least one car, it became de rigueur for developers to build according to these expansive street configurations, resulting in subdivisions that emphasized homeowners’ privacy at the expense of any real walkability.  With homes spaced much further apart, yards were larger, and no amenities stood conveniently within walking distance, even back on the collector or arterial that provided access to the subdivisions.  Nobody who bought into these developments gave any consideration that they would get anywhere except by car. Quite a few developments built during the 60s and 70s didn’t have sidewalks.

Housing from this time period isn’t as abundant as are the examples from the 1950s, because fewer households were organizing into families.  A moderate baby bust followed the boom.  Interestingly, home sizes grew even as the birth rate plunged; thus, individual households had more space to their own than any time in history—both inside and outside the house. Demand for shared green space reached a nadir.  Public parks in these regions are particularly scarce, since private yards typically sufficed.  The few parks in Upper Bucks County must devote a significant amount of space to parking lots, because they are inevitably unreachable by foot.

It was this time period that the cul-de-sac evolved from a suburban novelty to a sine qua non in subdivision development; families soon specifically sought them out.  The early 1960s developments often didn’t even bother with the circular patch of pavement that allowed vehicles to turn around; the roads just terminated in dead ends, particularly when these new suburbs were pushing into unincorporated areas well beyond the inner-ring suburbs.  Most municipalities eventually required roads to end in cul-de-sacs.  While the curvilinear configuration of the 1950s remained popular, by this point many of the streets in a subdivision terminated in a court.  The lack of a thruway discouraged all cars except for those belonging to people who lived on that cul-de-sac, dramatically lowering traffic volume, increasing privacy and giving the suburban subdivision a quiet, low-density settlement pattern that almost resembled rural living. 

I’m not sure when the next subtle generation in subdivision design truly emerged, but it would probably correlate to the late 1970s and early 1980s, when the now-adult Baby Boomers began starting their own families—the echo boom.  Household formation picked up pace, and these young families generally sought new construction just as their parents had.  While some of the new developments took on an expansive form—particularly the luxury ones or those where land was cheap and abundant—quite a few homebuilders tightened the design.  In many cases, average lot sizes retreated slightly, even while square footage to the homes continued a steady growth.  Perhaps recognizing that they had renounced too many neighborhood essentials (or perhaps because more municipalities began mandating them), the developers of suburbs from the 1980s and onward regularly featured amenities such as storm sewers, curbs, and sidewalks (at least on one side of the street).  As a compensation for the slightly smaller yards, these subdivisions (particularly the larger ones) would often include some shared open space in the form of greenery around a decorative retention pond, a community clubhouse, or a soccer field.

Why did this happen? Why did subdivisions return to a slightly higher, more urban density than the decades prior?  My own suspicion is that some of it was prescriptive: through ordinances, municipalities started requiring culs-de-sac instead of dead ends, or storm sewers instead of drainage ditches, which drove up development costs.  Also, formerly unincorporated lands began incorporating and immediately raising the minimum standards for subdivision design.  Developers, in turn, couldn’t necessarily pass these imposed costs directly to the consumer, so instead they found a trade-off with smaller lot sizes, squeezing more homes into a newly platted piece of land.  The result looks something like the quintessential 1980s/90s suburb below:

If this photo looks unusually flat for something in Pennsylvania, that’s because it isn’t Pennsylvania.  The subdivision pictured above is in the outskirts of Baton Rouge, Louisiana.  While such a shift in location may seem eccentric or even unexplainable, Baton Rouge offers much more abundant examples of the 1980s subdivisions, having grown considerably at a time when the more mature metro of Philadelphia was fairly stagnant.

This subdivision also demonstrates another, subtler evolution in street design: the 90-degree cul-de-sac.  Notice the shift in the street from the photo below, as well as the parallel sidewalk.

The buffer strip between the sidewalk and the street seems a bit larger than normal, but other than that, nothing is likely to catch the eye as out of the ordinary.  But then, upon entering the bend in the road, the sidewalk takes a more generous cut into people’s front yards, veering strangely close to their front porches. 

Why would they have done this?  It almost appears to me that authorities approved the site plan without thoroughly vetting it.  While there’s nothing wrong per se about having a sidewalk so close to a house, it’s also hard to see why the average buyer would prefer it to a parcel where the sidewalk is much closer to the street.

Elsewhere, in a similar neighborhood down the road, one can witness another insertion of the cul-de-sac into a 90-degree-turn.  Though the homes are more modest, the design of the sidewalk seems a bit more conventional, and, as a result, more effective.

But look at the grassy island in the middle.  The lawn is poorly maintained, and the absence of any other landscaping makes it seem like an afterthought—like some sort of padding.

In neither of the two above examples is the execution as effective as it should be, which makes me suspect that the developers really didn’t know what they were doing.  Or they didn’t care.  It’s not a tough concept, though if these worm’s-eye photographs don’t convey it, this bird’s-eye Google Map should, taken from a subdivision of similar design in the same part of town.

Notice how the 90-degree bends stretch into curvy culs-de-sac?  This road design is a shrewd method to make a little more money by cramming an additional parcel or two into the same space.  If the road were to employ a conventional l-shaped bend, the lots that directly front the bend would be even more strictly wedge shaped, to the point that the street frontage wouldn’t be wide enough to allow individual driveways.  Or, one house would claim an enormous side yard from the land that is completely unreachable by a driveway.  With a gentle arc in its place, each house gets more or less the same linear footage as access to the street, and the surveyors who put together the original plat could fit in another parcel or two.  And a more conscientious developer could transform grassy patch in the center of the cul-de-sac into an attractive, verdant amenity.

There’s nothing subversive or unethical about this design; it simply demonstrates that, particularly for moderate or middle-income households, developers have learned they can slice away at some of the yard size.  The homes featured in the photos and map above all come from Gardere, a lower and moderate-income area on the otherwise affluent south side of Baton Rouge.  My suspicion is that these subdivisions exist through some form of Low-Income Housing Tax Credits: they’re newer, in better condition, and bear some of the “neo-traditional” design features that federal housing programs love to employ.  Because the average buyer for these properties doesn’t have the money to be choosy, developers can take huge liberties, and they don’t necessarily worry about details like attractively landscaped common area or well-designed sidewalks.  And, in the grand evolutionary arc (pun fully intended) of American settlements, this represents one more design strategy pushing us further from the look and feel of the original Levittown.  Suburban developments are neither uniform nor unchanging.  I’m not confident that the conventional grid will ever become the standard again, even though New Urbanist advocates have successfully implemented it in specialized niche developments throughout the country.  (After all, does anyone openly claim to be a New Urbanist anymore?)  But I absolutely trust that culs-de-sac and street curves have a long way to grow before the design calcifies.  And it probably never will.  The evolution continues.

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6 thoughts on “Not a fork in the road as much as a spoon.

  1. Emily Kennedy

    Eric, the street where I grew up ended in a dead end, had drainage ditches and no sidewalks. I’m pretty sure it was built in the late 50s or 60s, which would be consistent with the things in your article.

    1. AmericanDirt

      Hey Emily, thanks for the comment! I definitely know what you’re talking about. I’d be willing to bet the farm that part of the reason your street didn’t have those amenities (sidewalks, storm sewers) is because, back when the land was subdivided and the homes were built, it was still in unincorporated Indianapolis…so they didn’t have nearly as strict of rules. This was before 1970’s Unigov, of course. But there’s a lot to be said about those neighborhoods from the 1960s–by now they have nice mature trees and great canopy, they feel kind of secluded, and I think that a lot of the homes used better building materials than the ones that came 20 years later. Not surprisingly, they also seem to host the majority of the mid-century modern homes, which have started becoming trendy again. Good observations!

  2. Jeffrey Jakucyk

    A study of the whole array of different street grid and development patterns could fill an entire book, and it’s really quite fascinating. A particular aspect that I’m interested in is when suburban subdivisions started turning their backs to their collector/distributor/arterial access roads. It seems like well into the 1970s, even as the street layouts became more curvilinear and disconnected, you still had houses facing the pre-existing roads, even as new streets were built within the subdivision.

    By the time we get to the 1980s however (maybe earlier out on the west coast or other sunbelt areas that boomed in the post-WWII period), with the rise of gated communities, many other subdivisions started to mimic that style with only a single point of entry and all the houses arranged around the new interior street network. This is great for traffic “engineering” if not traffic itself, not to mention how it completely cuts off any possibility of pedestrian or bike access, but it means that all the main roads are at the backs of houses. Whether there’s a wall, a fence, or landscaped berms, the main streets are a sort of nebulous no man’s land that has to be maintained entirely by the municipality and/or the homeowner’s association. No individuals have any ownership of it, either implicitly or expressly.

    This seems to be the logical (if wretched) conclusion of the dendritic/hierarchical street network, which I suspect is actually more wasteful and expensive than the grid it replaced, and which was itself thought to be overly redundant and expensive. With the entire perimeter of a subdivision having no frontage, that means you have only one building lot (plus some berms/walls/whatever) between the main road and the interior street, which is very wasteful to say the least. That, and all those cul-de-sacs, which are none too cheap either.

  3. AmericanDirt

    You raised a great point, Jeffrey. The neighborhood I grew up in was probably platted in the early 1980s, and homes started going up around 1984 or 85. It still has houses fronting the original collector road. Those lots have always been worth less than the homes in the interior of the subdivision, though, and the people who live in those homes have often complained about feeling left out of neighborhood association decisions.

    I agree with you that the newer design (where all homes in a subdivision turn their backs to the original collector/arterial) seems to be wasteful, since you have only one home between the main road and the interior street. But that is now the norm–echoing the layout of a gated community, as you wisely noted. I guess developers realized that the homebuyers greatly prefer the backs of their homes facing a major street rather than the fronts of their homes. And it may be so extreme that the added cost of building extra road is offset by the depreciated value of those lots that front a collector/arterial.

    No doubt there just isn’t much of a market (among the suburban minded community, at least) to live with front yards facing a busy street.

  4. Jeffrey Jakucyk

    The problem of course is that it’s all self-reinforcing. The more subdivisions turn inward the less pedestrian, bike, and transit friendly they are, the more traffic is generated, and thus the more hostile those collector and arterial streets become, leading to more inward facing, more buffering, more spacing out, and more traffic. Before long you end up with a situation like the one in Orlando where it’s a 7 mile drive to visit the neighbor on the other side of your back yard fence.

  5. AmericanDirt

    Yep, Streetsblog helped that aerial go viral (relatively speaking). Alas, I suspect the increasingly “introverted” street design that you pointed out–where more and more subdivisions are modeled after gated communities–sells well. And, of course, we are getting more development-driven amenities that get paid for and maintained through annual neighborhood association dues. So these contemporary subdivisions have nature trails, clubhouses, pocket parks, even forest preserves all within the original site plan…so in a way, they are more pedestrian friendly than the subdivisions of the 1970s, but completely turned within themselves. And more cul-de-sacs than ever.


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