How Road Design Makes Housing More Expensive
Housing construction in America often occurs in subdivisions. Whether located in urban infill contexts or suburban greenfields (more often the case), these are standalone private developments with their own internal infrastructure. Seldom do they have real autonomy, though. They’re still subject to single-family zoning and other land-use regulations, which make many such communities exclusive. And another, less covered regulatory regime that drives up their costs is the road networks. They are full of the wide, multi-lane roads and culdesacs associated with suburbia—many of which the developers were forced to build.
“Subdivisions” refer, as the name implies, to formerly intact property parcels that were split up into separate plots. They sometimes have their own internal rules for water, sewer, parks, and rights-of-way. Like much postwar development, they conform to road design recommendations that produce a development form that is car-reliant and hostile to walking.
Some of this is due to their internal, market-driven guidelines (for example culdesacs are viewed by developers as a way to sell safety and privacy). But government policy plays a role. In many localities, subdivision roads must be wide enough to accommodate highway-like speeds and vehicle throughput, thanks to antiquated beliefs among traffic engineers.
Texas has thousands of subdivisions thanks to their municipal utility district policy, which grants developers relative autonomy to build what are basically small private cities. But Texas counties still have the authority to require subdivisions to include roads that can be 50 to 100 feet wide in the case of arterials, or 40 to 70 feet wide in other cases. The “shoulder to shoulder width” in Texas subdivisions are a minimum of 25-32 feet “within the right of way.” In Henderson County, North Carolina, roads except alleys must have a 30-50 foot width. Similar regulations are found at municipal level nationwide.
But the dictates also come from state transportation departments. Virginia’s DOT recommends that subdivision roads allow most vehicles to travel up to 30 mph. The state’s guidelines also establish standards for planting strips and rotary islands.
It all plays out in the development company I work for, which has spent 40 years building a large subdivision in Charlottesville. The earliest road in that project is 17 feet wide and runs narrowly through a wooded area. This causes people to intuitively drive slow, meaning the road has never been prone to accidents. The regulatory manual for streets at its time of construction was, according to the project developer, only 4 pages.
The road going through a phase that’s under construction now will be about 21 feet wide. The shoulders on both sides have dozens of feet of clearance before leading into the woods, making it feel like a major thoroughfare cutting through a low-traffic forested community. The manual that dictates its construction standard is hundreds of pages. Overall, it will lead to faster driving once the road is complete.
Subdivisions must often build more roads than are necessary due to adequate public facility ordinances, a policy found in many jurisdictions. Under this rule, according to Maryland planner Bryan Barnett-Woods, planners block projects from proceeding if the infrastructure, including roads, is by their somewhat arbitrary standards insufficient to meet demand (a common Nimby criticism of new development). APFOs require either developers or local authorities to build new roads that would ostensibly facilitate greater throughput. In short, it’s a mandate for more roads, which must have greater widths, more signage, thicker pavement, and other bells and whistles.
Lastly, there are often federal regulations that are either mandated onto, or serve as advisory information for, local roads. They pertain to ADA, fire safety and more.
It’s already well-documented that this over-engineering, when done for public roads, raises costs for taxpayers. Less covered is how it raises home costs for residents within private subdivisions. Like any cost of business, developers pass road standard costs onto consumers – i.e. homebuyers and renters. For example, paving a subdivision road tends to cost, according to a ChatGPT analysis, about $75 per linear foot. The bot estimates that widening a road from 17 to 20 feet would add $69,000 per mile.
And that’s just for paving. The blog Kobo Building estimates that per linear foot costs for full road construction are between $1,500-$2,000, so the widenings really add up for individual residents.
A 2006 University of North Carolina study found that AFPOs tend to drive up the cost of housing in general. While some jurisdictions have tweaked their AFPOs to reduce this impact, these regulations still create waste.
The intent of such rules is to help subdivisions handle the traffic they create. But there is a wide history of U.S. subdivisions, particularly those from the early 20th century, that built narrow roads, just as municipalities once did. Both turned out fine. Moreover, the actual free market seems to build roads more narrow when left with the choice, as is evident in the rise of New Urban-style megaprojects here and abroad.
Ideally, such rules would be either abolished or replaced with more targeted measures. Virginia, to its credit, allows for an alternate review process for “neotraditional” development that enables urban development styles. The policy still requires individual review for such projects, but ideally this is the sort of road standard that would be allowed by-right. It would still be an improvement to the burdensome, expensive status quo.
This article featured additional reporting from Market Urbanist content staffer Ethan Finlan.
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