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Finding and Using GIS Data

The AGS Library's Guide to Finding GIS data and working with it for your specific project needs

Stanford Open Policing Project


Stanford Open Policing Project


About: Police traffic stop data is available from this site for select locations across the United States. It is standardized to be able to make direct comparisons between locations, despite having been collected from various sources. In addition to providing access to the raw data, the site also provides scholarly analysis of the data as well as tutorials for how to use it for your own research.

Data Available: Tabular data is downloadable in either CSV or RDS (for R statistical software) format. Select locations also have GIS shapefiles available for download.

Topics Include: Location and time of traffic stop, race, age, sex, reason for stop, whether a search was conducted, outcome (warning, citation, etc.), and more. For Wisconsin, statewide data for traffic stops by state police is currently available, as well as for the city of Madison.


How to get GIS data

1. Navigate to the data download page by clicking "Data" at the top of the page.

2. Scroll down to find your desired location.

3. Review the attribute categories included in the dataset you wish to use (a black square under an attribute heading means it is included in that dataset.)

Table showing available attributes for sample datasets

4. In the "Download" column, click the desired file type. CSV file type iconfor CSV, RDS file type iconfor RDS, or GIS Shapefile iconfor GIS shapefiles (where available).

5. Save the file to the desired location.

6. Be sure to read the associated "Read Me" file to be able to accurately interpret the data.

Performing statistical analysis

Tutorials are included on the site to learn to use R to perform various statistical analysis. Click the "Tutorials" tab at the top of the page or head directly there by clicking this link:

Request Data from the AGSL

Still Stuck?

If you are having trouble finding the data you are looking for, the AGS Library may be able to help.

  • Use the buttons below to view our Geospatial Data homepage, request data from our collection, or e-mail us with questions.
  • You can make an appointment for an in-person or virtual consultation, just e-mail
  • We are located in the Golda Meir Library at UWM on the 3rd floor of the East Wing. Phone: (414) 229-6282.
Geospatial Data Homepage Data Request Form E-mail us