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The Shift Length Experiment

What We Know About 8-, 10-, and 12-Hour Shifts in Policing

Most law enforcement agencies have traditionally deployed their patrol officers based on a 40-hour workweek in which personnel work five consecutive, 8-hour shifts, followed by two days off. In recent years, however, an increasing number of agencies have moved to some variant of a compressed workweek (CWW) schedule in which officers work four 10-hour shifts per week or three 12-hour shifts (plus a time adjustment to make up the remaining four hours of the standard 40-hour workweek). While this trend towards CWWs has been moving apace, there have been few, if any, rigorous scientific studies examining the advantages and disadvantages associated with these work schedules for officers and their agencies.

This report presents the results of the first known comprehensive randomized experiment of CWWs in law enforcement. The Police Foundation experiment was designed to test the impacts of three shift lengths (8-, 10-, and 12-hour) on performance, health, safety, quality of life, sleep, fatigue, alertness, off-duty employment, and overtime among police. In addition to scientifically rigorous research design and methodology, the number of reliable outcome measures employed to analyze the impact of shift length, including departmental data, laboratory simulations and exercises, and previously validated self-report instruments, make this study one of the most comprehensive ever undertaken in this area. The experiment was conducted in the Detroit (MI) and Arlington (TX) Police Departments between January 2007 and June 2009.

The study found some distinct advantages of 10-hour shifts and identified some disadvantages associated with 12-hour shifts that are concerning. It is important that agencies implement strategies and policies that are evidence based, and the findings of this study provide important information for law enforcement leaders and other policy makers to consider when examining both the most efficient and effective practices for their agency, as well as the safety and quality of life of their personnel and the public they serve.

The Police Foundation's shift length experiment has received the 2012 Outstanding Experimental Field Trial Award from the Division of Experimental Criminology/American Society of Criminology (ASC). The award recognizes a single research project or program that contributes significantly to criminological research and experimental science.


Multimedia Resources

Dr. Karen Amendola Discusses the Shift Length Experiment

NIJ-Harvard webinar, Healthy Officers are Safe Officers: The Nexus Between Performance & Health.
Available Online

Dr. Karen Amendola's presentation on the shift length experiment at the June 2012 NIJ Conference.
Available Online

Listen to the January 2013 Office of Community Oriented Policing Services (COPS) podcast on the shift length experiment.
Available Online


In the Media

The March 2013 issue of Police Chief contains a research-in-brief of the shift length experiment.
Available Online

The April 2013 issue of COPS Dispatch contains an article by Drs. Karen Amendola and David Weisburd on the shift length experiment.
Available Online


Publications Documenting the Shift Length Experiment

The Shift Length Experiment: What We Know About 8-, 10-, and 12-Hour Shifts in Policing

Karen L. Amendola, David Weisburd, Edwin E. Hamilton, Greg Jones, & Meghan Slipka (Police Foundation Report; December 2011)
Available Online
. Printed copies ($10.00 includes S&H) can be ordered by contacting us.

An Experimental Study of Compressed Work Schedules in Policing: Advantages and Disadvantages of Various Shift Lengths

Karen L. Amendola, David Weisburd, Edwin E. Hamilton, Greg Jones, Meghan Slipka
Journal of Experimental Criminology, December 2011, Volume 7, Issue 4, pp. 407-442.

Final Report to the NIJ: The Impact of Shift Length in Policing on Performance, Health, Quality of Life, Sleep, Fatigue, and Extra-Duty Employment

Karen L. Amendola, David Weisburd, Edwin E. Hamilton, Greg Jones, & Meghan Slipka (December 2011)
Available Online:
Executive summary
Final report submitted to the NIJ


Results of a Random National Survey of Police Agencies

As part of the shift length experiment, the Police Foundation conducted a random telephone survey of 300 police agencies to determine the proportion of agencies that have adopted compressed schedules. We also examined variables based on agency size and the use of shift rotation, as well as trends associated with each over time. The purposes of this telephone survey, conducted first in November 2005 and again in November 2009, were to determine the proportion of agencies that use compressed shift schedules (e.g., 8-, 10-, or 12- hour shifts, or some variation) for their field patrol officers, and to identify the extent to which agencies employ rotating shifts. The first report below is a comparison report of the survey results in Time One and Time Two.

Trends in Shift Length: Results of a Random National Survey of Police Agencies

Karen L. Amendola, Meghan G. Slipka, Edwin E. Hamilton, with Michael Soelberg and Kristen Koval (December 2011)
Available Online

Law Enforcement Shift Schedules: Results of a 2009 Random National Survey of Police Agencies

Karen L. Amendola, Meghan G. Slipka, Edwin E. Hamilton, Michael Soelberg (November 2011)
Available Online

Law Enforcement Shift Schedules: Results of a 2005 Random National Survey of Police Agencies

Karen L. Amendola. Edwin E. Hamilton, Laura A. Wyckoff (May 2006; revised November 2011)
Available Online