The Stanford Open Policing Project: Uncovering the truth behind traffic stops


On a typical day in the United States, police officers make more than 50,000 traffic stops. But what do we really know about these stops?

Until The Stanford Open Policing Project, a national repository detailing interactions between police and the public didn't exist. There was no way to interrogate patterns across traffic stops and uncover stories hiding within these trends.

To combat this data deficiency, the Stanford Open Policing Project was launched to collect and standardized data on vehicle and pedestrian stops from law enforcement departments across the United States. 

Since its start in 2015, the project has gathered 130 million records from 31 state police agencies, with an eye to begin collecting data on stops from law enforcement agencies in major cities as well. And all of this information is being made freely available.

The data

Standardized stop data are available to download on a state-by-state basis from the project's website. Data includes a subset of common fields for each state, such as stop date, time, location, driver's race, driver's gender, stop reason, and more.

Image: A snapshot of the project's data.

Learn how to use the data in your own work

The project also includes a tutorial section to help other journalists leverage the its data. In this section, you can learn how to analyze the traffic stop data and apply key statistical tests to measure racial disparities and possible bias, with the help of video and prewritten R code.

Explore the project here.