Why Your City’s Street Grid Matters More Than You Think
The Hidden Impact of Street Connectivity on Transportation, Housing, and Connectivity
The Manhattan street grid is remarkably intuitive. If you stand at the intersection of Third Avenue and 125th Street, you’re exactly 75 evenly spaced blocks north of Third Avenue and 50th Street. It’s like a game of Battleship—even visitors can navigate the grid within a day or two.
Historically, pre-automobile street grids emerged in two ways: intentional planning and organic development. Some cities, like Washington, D.C., were meticulously designed. Pierre L’Enfant laid out its grid more than two centuries ago, incorporating diagonal arterial streets for connectivity and grandeur. In contrast, Boston’s street network evolved haphazardly, shaped organically by colonial-era walking paths, resulting in its famously narrow and irregular streets.
Despite the urban sprawl that has dominated North America since World War II, most cities still have a gridded main street or downtown core, with the street network becoming more disordered as development spreads outward.
Omaha, Nebraska, illustrates this shift. Its downtown—the city’s easternmost area—follows a structured grid. But as development sprawled westward, coinciding with the rise of car ownership, the street network became increasingly disordered.
Modern suburbs, particularly those built around cul-de-sacs, reflect this shift even further. However, not all suburbs follow this pattern. Older suburbs, such as Evanston, IL, retain a more traditional street grid, while newer developments, like many in Columbia, SC, are dominated by winding disconnected cul-de-sacs. Aerial imagery alone would make it difficult to classify one as a city and the other as a suburb.
So why does any of this matter? On an individual level, it might not. But when it comes to government policy, urban growth, and transportation, the structure of our street networks plays a crucial role.
Here’s why:
Transit
Network design is just as important as the service provided by a transit agency. The ability to reach a destination quickly and conveniently is essential for transit to compete with the individual freedom that cars provide. In its most efficient form, a transit network operates on a grid of well-defined corridors, requiring minimal adjustments over time.
San Francisco is a prime example. With its 7 mile x 7 mile street grid, major roads align neatly with transit routes, ensuring that most trips require no more than a single transfer. Because every bus route intersects predictably, riders can navigate the city efficiently without excessive detours.
Beyond convenience, a well-structured transit grid is also far more cost-effective and geometrically efficient. Consider two areas with predominantly low-density, single-family housing:
Lubbock, TX: A nearly perfect grid with arterial roads spaced in 1x1 mile blocks. If bus routes were placed along these roads, each would serve approximately 1,400 buildings per mile within a half-mile walking distance.
Columbia, SC: A fragmented, disordered street network. Due to the lack of a cohesive grid, it is much harder to design transit routes that effectively serve a walkable population. As a result, a bus route would reach only about 650 buildings per mile within the same half-mile radius (most are not within walking distance to the bus route).
Since bus transit operates with fixed costs regardless of ridership, a well-structured grid dramatically improves efficiency. In this example, a bus network in Lubbock would be 215% more effective at serving potential riders compared to Gwinnett County—simply due to the topology of the street network while adding no apartments.
Growth
This might be the most significant issue: the sprawling, haphazard network of cul-de-sacs that dominate the outskirts of our cities and metro areas. These winding streets and large lots effectively lock in low-density development, making it difficult—if not impossible—to introduce missing middle housing when a place needs to grow.
By contrast, Houston’s urban core remains largely gridded and, famously, has no zoning restrictions. This flexibility has allowed neighborhoods like Rice Military to evolve organically. Within a grid, an entire block can be redeveloped into a large apartment building, a row of single-family homes with large yards, or a mix of both—without the constraints posed by isolated, master-planned subdivisions.
The inefficiencies of suburban street networks extend beyond housing. Take, for example, a subdivision in Union County, NC, which contains 221 single-family homes. Due to the design of its road network, 45% of the land owned by the HOA is wasted on dead space, providing no public or private amenity.
Now, imagine keeping every existing home and lot exactly as it is, but restructuring the remaining land into a grid. This simple change would more than double the population within the same footprint.
To put this in perspective:
Union County, NC spans 639 square miles.
If the existing suburban density of this housing development were applied across the entire county, its population would be 1,024,596.
If the same area were developed efficiently - with a maximized street grid that kept the same density of single family homes—it could support 2,257,108 people, simply by eliminating wasted space.
Transportation and Connectivity
With modern development often lacking central planning, the absence of interconnected grids has led to disjointed neighborhoods. Today, large tracts of land are purchased by developers who construct master-planned communities within their own boundaries. However, these developments rarely consider the layout of surrounding areas, resulting in isolated neighborhoods with no continuity or connectivity.
A clear example of this can be found in the suburbs of Charleston, where five separate housing developments sit adjacent to one another—yet function as entirely separate entities. Residents of these communities have little to no interaction with their neighbors outside their own development, largely because the road network discourages it. In the example below, homes marked in yellow are a 70-minute walk from the nearest home marked in red—despite their backyards touching.
But social disconnection isn’t the only consequence. The lack of porosity in these developments creates significant transportation inefficiencies:
Each subdivision typically has only one or two exits, forcing all traffic onto a few wide, car-oriented arterial roads, leading to bottlenecks.
In contrast, a well-designed grid distributes traffic across multiple routes, preventing congestion at a single choke point.
A grid also improves transit or driving efficiency—a single turn or transfer can connect riders or drivers to multiple destinations throughout a city.
School bus routes become far less efficient when neighborhoods are disconnected, requiring longer trips with multiple detours.
Emergency response times suffer because first responders are forced to take indirect routes through disconnected developments.
As an exercise, try mapping a bus route that efficiently serves all of these neighborhoods pictured above within a walkable distance. The inefficiencies quickly become apparent. This lack of connectivity isn’t just an inconvenience—it actively hampers mobility, safety, and community cohesion.
But most great cities aren’t a grid!
Some of the most walkable and beautiful cities in the world don’t follow a true grid. Many were shaped by the organic growth of walking paths in ancient cities like Rome, Venice, and Istanbul.
The key difference is that these cities are highly porous, with an intersection density far greater than modern suburban sprawl. Take Charlotte and Rome, for example—both have some of the most disordered street networks, according to the research shown above.
While neither follows a strict order like Chicago’s nearly perfect grid, their connectivity makes them far more conducive to walking, transit, and future growth.
Once again, I challenge you: design an efficient bus or transportation system for both of these topologies and tell me which is radically easier.
The Difference
Our cities would look radically different today if they had retained their historic street grids as they grew. Places like West University Place and Columbia, SC, pictured here, consist entirely of single-family homes. However, their layout results in 2.5 times higher density and significantly greater walkability.
Additionally, the walkability of these two places differs dramatically. From the top left to the bottom right in the image, West University Place takes 21 minutes to walk end to end, whereas in this outlying neighborhood of Columbia, SC, it takes 111 minutes (following sidewalks).
If the single-family neighborhood density of West University Place were applied to Indianapolis, the city would have a population of 2.8 million people—1.9 million more than today—solely due to differences in street grids and more efficient lot sizes. Yet, in this scenario, everyone would still have a yard and a single-family home.
I know many people disagree with me, arguing that street networks are not as significant an issue as density. However, I believe that a well-connected and porous city makes the difference between knowing your neighbor who shares a fence line with you—or not.
While we cannot structurally fix the problem of disconnected communities, we can at least highlight the physical and social isolation caused by myopic developers building isolated subdivisions with little regard for community.