Version Date: May 20, 2024 View help for published
Principal Investigator(s): View help for Principal Investigator(s)
Longrong Pan, University of Michigan. Institute for Social Research;
Robert Melendez, University of Michigan. Institute for Social Research;
Philippa Clarke, University of Michigan. Institute for Social Research;
Grace Noppert, University of Michigan. Institute for Social Research;
Lindsay Gypin, University of Michigan. Institute for Social Research
Series:
https://doi.org/10.3886/ICPSR38585.v2
Version V2 (see more versions)
This collection contains measures of primary and secondary roads (highways and main arteries) per United States census tract and per United States ZIP code tabulation area (ZCTA) in 2010 and 2020. These measures may be used as a proxy for heavy traffic, high traffic speeds, and impediments to walking or biking. Variables include: counts of primary, secondary, and all streets per tract and per ZCTA; total length of primary, secondary, and all streets per tract and per ZCTA; ratio of primary and/or secondary road counts to all roads; and ratio of length of primary/secondary roads to all streets.
Export Citation:
census tract and ZIP code tabulation area
Data users interested in walkability and neighborhood disamenities (such as pollution and traffic) might find useful data in these other NaNDA datasets:
Data users interested in other resources that contribute to walkability, such as parks, public transit, and retail and other destinations, may find the following additional NaNDA datasets to be of use:
In order to investigate the impact of disamenities (Weiss et al., 2011) on neighborhood walkability, this study describes the number and proportion of primary and secondary roads per census tract and ZIP code tabulation area in the United States.
The research team used ArcGIS Desktop and the 2010/2020 TIGER/Line all lines (edges) shapefiles for all U.S. counties to identify edges that represented three types of roads: primary roads (limited-access highways with on- and off-ramps and are typically part of the interstate or state highway system), secondary roads (two or more lanes, intersect directly with other roads, and are generally part of a state or county road system), and all streets. Classification of roads as primary or secondary is based on the MAF/TIGER Feature Class Code (MTFCC), a five-character code used to classify features of the landscape and built environment (U.S. Census Bureau, 2016). The team then assigned roads to census tracts/ZIP code tabulation areas (ZCTA) using the TIGER/Line topological faces shapefile.
To create the final datasets, the team aggregated the total number and length of all streets, primary roads, secondary roads, and both primary/secondary roads per census tract/ZCTA, as well as calculated ratios of total primary and/or secondary roads to all streets and length of primary and/or secondary roads to length of all streets.
Census tracts and ZIP code tabulation areas in the United States, excluding U.S. island territories.
Data and documentation for the ZCTA-level data were originally deposited in openICPSR project 159941.
United States Census Bureau. "TIGER/Line Topological Faces Shapefile, 2010 Census Geography (2010 Version)," 2010.
United States Census Bureau. "TIGER/Line Topological Faces Shapefile, 2020 Census Geography (2020 Version)," 2021.
Data and documentation for the census tract-level data were originally deposited in openICPSR project 159902.
United States Census Bureau. "TIGER/Line All Lines Shapefile, 2010 Census Geography (2010 Version)," 2010.
United States Census Bureau. "TIGER/Line All Lines Shapefile, 2020 Census Geography (2020 Version)," 2021.
United States Census Bureau. "Decennial Census 2010, Summary File 1, Geographic Header Files," 2010.
2022-11-10
2024-05-20 DS3 (Primary and Secondary Roads by Census Tract 2020 Data) and DS4 (Primary and Secondary Roads by ZIP Code Tabulation Area 2020 Data) have been added with accompanying documentation. DS1 (Primary and Secondary Roads by Census Tract 2010 Data) and DS2 (Primary and Secondary Roads by ZIP Code Tabulation Area 2010 Data) and the accompanying documentation has been re-released to update the study title, cover pages, and data set names - no data changes have been made.
2022-11-10 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:
The public-use data files in this collection are available for access by the general public. Access does not require affiliation with an ICPSR member institution.
ICPSR usually offers files in multiple formats for researchers to be able to access data and documentation in formats that work well within their needs. If you have questions about the accessibility of materials distributed by ICPSR or require further assistance, please visit ICPSR’s Accessibility Center.

This study is provided by ICPSR. ICPSR provides leadership and training in data access, curation, and methods of analysis for a diverse and expanding social science research community.