Analysis of Police Vehicle Stops in Cincinnati: A Geographic Perspective

  • Lin Liu University of Cincinnati
  • John Eck University of Cincinnati
Keywords: Traffic Stops, Police Vehicle Stops, Racial Profiling, Policing, GIS


This study analyzes police vehicle stop data collected during the second half of 2001. In addition to addressing questions such as who is stopped and why vehicles are stopped, this article focuses on the geographic variation and racial variations of the stops in the fifty-two neighborhood areas of the City of Cincinnati. Racial disparities in vehicle stops are often linked to the controversial issue of racial profiling. A new measure, disproportioniality, is developed to better capture such disparities. Many earlier studies used census population as the baseline in calculating disproportionality indices, based on an implicit assumption that people only drive in the neighborhood where they live. A reasonable baseline should reflect how many people drive in a neighborhood and how many miles are driven in a neighborhood. This study replaces census population by vehicle miles as the baseline. An innovative approach is developed to estimate vehicle miles in each neighborhood. The research concludes that small disparities exist between Black and White drivers in Cincinnati while the magnitude varies significantly by neighborhood areas, and that the spatial pattern of stops appears to be associated with those of driving patterns, crime, drug calls, overall demand for police services, and traffic accidents. Specifically, the correlations between stopping rates for African-Americans and accident rates and minor crimes are particularly high.


Bureau of Transportation Statistics (BTS) (1995) Census of Transportation Planning Package CD, Washington D.C.: U.S. Department of Transportation.

Chen, Y. (1994) Bilevel Programming Problems: Analysis, Algorithms and Applications. Publication no. 984 at the Center for Research on Transportation, University of Montreal, Canada.

Engel, R., Shepard, J., Calnan, M. and Thomas, J. B. (2002) 'Theory and Racial Profiling: Shortcomings and Future Directions in Research. Justice Quarterly, 19: 249-274.

National Research Council (2003) fairness and Effectiveness in Policing: The Evidence. Committee to Review Research on Police Policy and Practices. Wesley Skogan and Kathleen Frydl, editors. Committee on Law and Justice, Division of Behavioral and Social Sciences and Education. Washington DC: National Academies Press (prepublication at http://books.nap.eclu/opcnbook0309084 334/htmllindcx.html.

Sampson, R. J. and Lauritsen, J. I. (1997) Racial and Ethnic Disparities in Crime and Criminal Justice in the United States. In Tomy, M. (ed.) Ethnicity, Crime and immigration: Comparative and Cross-National Perspectives. Crime and Justice, vol 21. Chicago: University of Chicago Press, pp. 311-374.

Sherman, I. and Eek, J. E. (2002) Policing for Crime Prevention. In Sherman, L. W, Farrington, D., Welsh, B. and MacKenzie, D. L. (eds.) Evidence-Based Crime Prevention. New York: Routledge. Pp. 295-329.