Street-network Sprawl in Cary, United States

What is Street-network sprawl?

Street-network Sprawl is a way to measure urban sprawl, worldwide, through the connectedness of the streets. Less sprawl means more connected, more walkable streets. Well-connected streets – like New York City’s grid – are more walkable and can be served by public transit.

The street network is permanent, and its connectivity affects the livability and environmental footprint of cities for decades and centuries to come. In places with more connected streets, residents drive less and walk more. A well-connected street network is associated with better outcomes for health, the environment, sustainable consumption, social integration, and equity.

We can quantify how connected street networks are with the Street Network Disconnectedness Index (SNDi).

SNDi -- our measure of street-network sprawl (disconnectedness)

The SNDi is a comprehensive measurement of “sprawl”. It captures:

A higher SNDi means less-connected streets – i.e., more sprawl. For the 10137 cities in our dataset, the average SNDi is 2.25, with half of the cities' SNDis falling between 1.08 and 3.25.

More information on the sprawl index can be found in these research papers:

To see the state of street-network sprawl across the globe, visit the sprawlmap.

Cary: city in North Carolina, United States

What exactly constitutes the spatial extent of the city? For these aggregations, we used the Global Human Settlement Layer Urban Center Database (GHS-UCDB) to define the boundaries of the city. These cities -- or urban centers -- cover areas that are densely populated and built-up, and so may extend beyond the spatial borders of these cities that we may be familiar with. The GHS area is shaded in blue.

View Cary, United States on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Cary as of 2014, the overall level of street-network sprawl is 6.32, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 4.66, 6.7, 6.95 and 5.24. Street construction in Cary increased in disconnectivity initially but has since improved. The streets constructed in 1991-2000 were the most disconnected.

Quantity of street network construction: The street network in Cary spans a total of 693 kilometers. It is dominated by roads constructed in 1991-2000. These roads have an SNDi of 6.95, which is highly disconnected.

Effect on the aggregate network: New construction in each period adds to the total stock of streets, but does not change streets that have already been built. Therefore, it has a limited effect on the street network as a whole. The SNDis of the aggregate street network in the respective time periods are 4.66, 6.1, 6.53 and 6.32. The aggregate street network in Cary increased in disconnectivity initially,but the trend has turned around after 2000.

Cary and North Carolina follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these peaked in 1991-2000.

How do development practices in Cary fare in comparison to others in North Carolina? Most recently in 2001-2014, street construction in Cary was the 7th-most disconnected out of the 8 cities in North Carolina. Its position in the ranks since 1975 has fallen; relative to other cities in North Carolina, street construction in Cary has become more connected. Cary ranked 1st in 1975, 3rd in 1976-1990, 5th in 1991-2000 and 7th in 2001-2014.

Cary and United States follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these peaked in 1991-2000.

How do development practices in Cary fare in comparison to others in United States? Most recently in 2001-2014, street construction in Cary was the 149th-most disconnected out of the 315 cities in United States. Its position in the ranks since 1975 has fallen; relative to other cities in United States, street construction in Cary has become more connected. Cary ranked 20th in 1975, 26th in 1976-1990, 65th in 1991-2000 and 149th in 2001-2014.

Cary and North Carolina do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Cary peaked in 1991-2000, while the SNDi of street constructions in North Carolina rose steadily.

To date, Cary is the 1st-most disconnected out of the 8 cities in North Carolina. Its position in the ranks since 1975 has not changed. Cary ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

Cary and United States do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Cary peaked in 1991-2000, while the SNDi of street constructions in United States rose steadily.

To date, Cary is the 7th-most disconnected out of the 315 cities in United States. Its position in the ranks since 1975 has risen; relative to other cities in United States, the street network in Cary has become more disconnected. Cary ranked 20th in 1975, 6th in 1976-1990, 6th in 1991-2000 and 7th in 2001-2014.

As of 2015, Cary had a built-up area of 37.98 square kilometers, and a population of 101641 people.

These are some other cities with approximately the same population: