The intersection-density indicator classifies municipalities into seven categories based on the relative connectivity of their street networks. The scores represent municipal averages of the U.S. Environmental Protection Agency’s ranked intersection-density variable, D3B_Ranked, which ranges from 1 to 20. Higher scores generally indicate a greater concentration of connected intersections, smaller blocks, and more route choices for pedestrians, while lower scores generally indicate disconnected streets, larger blocks, cul-de-sacs, or dispersed rural development.

Unlike the complete National Walkability Index, intersection density measures only one component of the built environment. A municipality may have a highly connected street network while still lacking nearby destinations, mixed land uses, sidewalks, transit access, or safe street crossings.

• Very High Intersection Density (17.32–20.00): Municipalities with exceptionally connected street networks, frequent intersections, relatively small blocks, and numerous alternative routes. These conditions generally support direct pedestrian movement and make destinations easier to reach on foot.
• High Intersection Density (14.60–17.31): Municipalities with well-connected street systems and relatively frequent intersections. Traditional street grids or compact development patterns usually provide multiple route choices for pedestrians, cyclists, and local traffic.
• Above Average Intersection Density (11.88–14.59): Municipalities with generally connected street networks but some variation among neighborhoods. Older districts may contain regular grids, while newer areas may include larger blocks, curvilinear streets, or less direct connections.
• Moderate Intersection Density (9.16–11.87): Municipalities with mixed connectivity. Connected downtowns or traditional neighborhoods may coexist with suburban development characterized by longer blocks, looping streets, and limited pedestrian route options.
• Below Average Intersection Density (6.44–9.15): Municipalities where disconnected or indirect street patterns are common. Larger blocks, branching streets, cul-de-sacs, highways, and separated developments may limit direct pedestrian movement.
• Low Intersection Density (3.72–6.43): Municipalities with sparse street networks and few intersections. Development is generally low density or dispersed, and walking routes may require substantial detours because relatively few streets connect directly.
• Very Low Intersection Density (1.00–3.71): Rural communities or highly dispersed suburban areas with extremely limited street connectivity. Roads may be widely spaced, disconnected, or designed primarily for automobile access, providing few practical route choices for pedestrians.

Planning Implications

Intersection density is a widely used indicator of street connectivity and urban design. More connected street networks generally provide shorter and more direct routes between origins and destinations, increasing the number of route choices available to pedestrians and reducing the distance required to complete some trips (Cervero & Kockelman, 1997; Ewing & Cervero, 2010).

Higher-scoring municipalities generally provide:

• More direct walking routes. A greater number of interconnected streets allows pedestrians to select shorter paths rather than relying on a small number of arterial roads or indirect subdivision entrances.
• Greater route choice. Connected grids distribute movement across several streets and provide alternative routes when a particular street is uncomfortable, congested, or inaccessible.
• Improved access between nearby destinations. Schools, parks, shops, transit stops, and residential areas are more likely to be physically connected when the street network contains frequent intersections.
• Greater potential for active transportation. Research has found positive relationships between intersection density, neighborhood walkability, and objectively measured moderate physical activity (Frank et al., 2005; Frank et al., 2006).
• Reduced dependence on a limited number of major roads. A connected network can distribute local trips across multiple streets rather than funneling nearly all movement onto a few arterials.

Lower-scoring municipalities may improve pedestrian connectivity by reconnecting incomplete street networks, adding pedestrian passages between cul-de-sacs and adjacent destinations, creating smaller blocks in new development, improving crossings of major roads, and requiring new subdivisions to connect with surrounding streets.

However, increasing the number of intersections alone does not guarantee a safe or comfortable walking environment. Intersection design, traffic speed, crossing distance, sidewalks, lighting, land-use mix, destination access, and transit availability also influence whether residents can realistically walk to daily needs.

Understanding Municipal Intersection Density

Municipal intersection-density scores provide a consistent way to compare one dimension of street-network design across communities. The data supplied for this analysis use the EPA’s ranked intersection-density variable rather than a raw count of intersections. For example, the dataset assigns San Francisco a score of 17.90, Seattle 17.75, Portland 17.61, Boston 17.58, and Philadelphia 17.04, placing each within the high or very-high categories.
Several major Sun Belt cities receive above-average rather than extremely low scores. Phoenix records 14.75, Miami 16.74, Houston 14.53, Dallas 13.88, Austin 12.71, and San Antonio 12.83. These results show that broad regional labels should not replace municipality-level analysis.
Municipal averages should nevertheless be interpreted carefully. A single score can conceal substantial internal variation. A city may contain a highly connected downtown grid, moderately connected residential neighborhoods, and disconnected peripheral subdivisions. The score identifies the municipality’s overall position on the ranked scale but does not show where connectivity is strongest or weakest within its boundaries.

The American Walkability Atlas can address this limitation by pairing municipal comparisons with neighborhood- or block-group-level mapping. This allows planners and residents to identify whether low connectivity is widespread or concentrated in specific parts of a community.

Geographic Patterns in Municipal Intersection Density

Municipal intersection density exhibits recognizable regional patterns that reflect differences in historical development, subdivision design, topography, and the timing of urban growth. Older municipalities in the Northeast and Midwest frequently exhibit higher intersection densities because many neighborhoods developed before widespread automobile ownership. These communities often retain interconnected street grids, shorter block lengths, and compact urban forms that support shorter travel distances, greater route choice, and higher levels of pedestrian connectivity. In contrast, many rapidly growing postwar municipalities, particularly in the South and West, contain larger blocks, curvilinear street networks, cul-de-sac subdivisions, and lower levels of street connectivity. These regional differences reflect historical planning practices and long-term patterns of urban development (Ewing & Hamidi, 2014).

• Northeast Corridor: Older municipalities frequently contain closely spaced streets, small blocks, and interconnected grids. Cities such as Boston, Philadelphia, Baltimore, and Washington, D.C., consequently record high intersection-density scores. The compact street patterns of these municipalities were largely established before automobile-oriented subdivision design became dominant.
• Great Lakes and Upper Midwest: Traditional industrial cities commonly retain connected neighborhood grids. Chicago scores 16.39, Minneapolis 15.96, St. Paul 15.67, and Milwaukee 15.71, indicating relatively strong connectivity despite later suburban expansion.
• West Coast: Several major West Coast municipalities score highly, including San Francisco, Seattle, Portland, Long Beach, and Oakland. Their scores reflect a combination of traditional grids, compact districts, and relatively connected urban street systems, although connectivity may vary considerably at the neighborhood level.
• Sun Belt: Intersection-density results are more varied than total walkability patterns might suggest. Some central cities and older municipalities retain connected street networks, while rapidly developed outer suburbs and exurban communities often contain lower-connectivity subdivisions. In Texas, for example, University Park scores 16.47 and Cockrell Hill 16.75, while Haslet scores 4.00, Combine 3.00, and Briar 5.00.
• Suburban Growth Areas: Municipalities dominated by postwar subdivisions frequently fall into moderate, below-average, or low categories. Curvilinear roads, cul-de-sacs, superblocks, gated developments, and limited connections between adjoining subdivisions reduce the number of direct routes.
• Rural and Dispersed Communities: Very low scores are especially common where roads are widely spaced and development is scattered. In these locations, low intersection density may reflect rural settlement patterns rather than a conventional suburban street design.

Within metropolitan areas, older central cities and inner-ring communities frequently record higher connectivity than recently developed outer suburbs. This pattern is consistent with research showing that street-network design is an important component of the relationship between the built environment and travel behavior (Cervero & Kockelman, 1997; Ewing & Cervero, 2010). It also reflects the broader transition from traditional interconnected street grids to postwar subdivision patterns organized around collectors, arterials, and cul-de-sacs.

Relationship to Walkability

Intersection density contributes to walkability by determining how easily pedestrians can move through the street network. Cervero and Kockelman (1997) identify design, including street characteristics, as one of the principal dimensions connecting the built environment to travel demand. Ewing and Cervero’s (2010) meta-analysis similarly treats intersection or street connectivity as an important built-environment measure associated with travel behavior.

Frank et al. (2005) found that intersection density, residential density, and land-use mix were positively associated with objectively measured moderate physical activity. Their combined walkability index was also associated with a greater likelihood of meeting recommended physical-activity levels. Frank et al. (2006) further connected neighborhood walkability with active transportation and health-related outcomes.

The indicator should not, however, be interpreted as a complete measure of pedestrian accessibility. High intersection density creates the structural potential for walking, but that potential is realized only when the connected network also provides safe crossings, pedestrian infrastructure, reasonable traffic speeds, and useful destinations.

Overall Pattern

Municipal intersection density closely reflects the historical development of American street networks. Older communities and traditional neighborhoods commonly achieve higher scores because they were developed with smaller blocks and interconnected streets. Newer suburban and exurban communities more often receive lower scores because their streets are organized around cul-de-sacs, limited-access subdivisions, and widely spaced arterial roads.

The dataset also demonstrates that intersection density and overall walkability are related but not interchangeable. Some municipalities possess relatively connected street networks without having the density, destination diversity, transit access, or pedestrian infrastructure needed to support extensive daily walking. Accordingly, the intersection-density score is most useful when presented as a focused measure of street connectivity and interpreted alongside the other components of the National Walkability Index.