Saturation Patrols

A saturation patrol is an increased number of police officers patrolling a specific area to look for impaired driving behavior, especially at times and in locations where impaired driving is more common. Saturation patrols are also called blanket patrols or dedicated driving while impaired (DWI) patrols.1 When implemented fully, saturation patrols are well publicized and regularly conducted.1 Just like sobriety checkpoints, the goal of saturation patrols is to increase the perceived likelihood that impaired driving will be identified and penalized, leading to a reduction in impaired driving.1 Saturation patrols are sometimes used when sobriety checkpoints are restricted by state or local laws.2

Effectiveness and Use of High-Visibility Saturation Patrols

One study examined associations between impaired driving prevention enforcement and the rate of self-reported alcohol-impaired driving by state.3 Rates of impaired driving were significantly lower in states that conducted saturation patrols.3 This relationship held for enforcement at both the state and local levels.3

Evaluations of saturation patrol programs in the Midwest have demonstrated that they can be effective. An evaluation of Minnesota’s NightCAP program using 1991–2005 data found an indication that patrols were reducing rates of alcohol-related fatal or severe injury crashes.4 However, the evaluation concluded that more patrols, better patrol visibility, and more associated advertising were needed to improve the impact of the patrols.4 A 2002–2003 demonstration program in Michigan consisted of weekly enforcement accompanied by some publicity, with an additional three mobilization blitzes with paid media.5 An evaluation of the program found that extensively publicized saturation patrols can be effective in reducing alcohol-related fatal crashes. The program saved an estimated 57 lives in one year.5 In contrast, an analysis of 2013–2017 data from the City of Los Angeles found that while the week following a sobriety checkpoint had a decrease in alcohol-involved motor vehicle crashes, no daily, weekly, or monthly effects were found for saturation patrols.6 The authors suggest this is because of the higher visibility of sobriety checkpoints.6

A 2010–2011 survey of law enforcement agencies in the United States found that 96% of state and 63% of local law enforcement agencies had conducted at least one saturation patrol in the past year.7 In the same survey, only 35% of state law enforcement agencies had conducted saturation patrols weekly or daily in the past year.7 Similarly, a 2012–2014 survey of law enforcement agencies in the United States found that 98% of state, 89% of municipal, and 84% of county law enforcement agencies conducted saturation patrols.8 Of the state law enforcement agencies who perform saturation patrols, 38% conducted them daily or weekly.8

Recent or Current Legislation by State

Saturation patrols are legal in all jurisdictions.1

Costs of High-Visibility Saturation Patrols and Time to Implement

The two main costs to implement saturation patrols are law enforcement personnel and paid publicity.1 Publicity is essential to the success of saturation patrols. Some publicity may come from earned media like news stories, but paid media like radio ads may be necessary and can be costly.1

If officers are already trained in detecting impaired drivers and conducting standardized field sobriety tests, saturation patrols can be implemented within 3 months.1

Other Issues and Resources

You can read Chapter 1, Section 2.2 of NHTSA’s Countermeasures that Work: A Highway Safety Countermeasure Guide for State Highway Officespdf iconexternal icon (Tenth Edition, 2020) to learn more about the topics above or other issues related to saturation patrols, such as publicity and arrests.1

More information about saturation patrols is also available in NHTSA’s Increasing impaired-driving enforcement visibility: Six case studiespdf iconexternal icon.9

You can read the RAND Corporation’s final reports for MV PICCS 1.0/2.0external icon and MV PICCS 3.0external icon for more information about how effectiveness and costs were incorporated into the MV PICCS tool for this intervention.


In the 1980s, alcohol-impaired driving gained attention in the United States with the advocacy of citizen organizations, advances in the collection of data about alcohol-involved crashes, and legislative changes.10 Throughout the decade, impaired driving enforcement changed, including the addition of roadside use of hand-held preliminary breath test devices and an increase in sobriety checkpoints and saturation patrols.10

A law enforcement bulletin from 2003 suggests that saturation patrols have been in use longer than sobriety checkpoints and have had a variety of names.11 For example, Minnesota began implementing its saturation patrol program called Operation NightCAP (Concentrated Alcohol Patrol) in 1998.4


  1. Venkatraman, V., Richard, C. M., Magee, K., & Johnson, K. (2021). Countermeasures that work: A highway safety countermeasures guide for State Highway Safety Offices. (Report No. DOT HS 813 097). Washington, DC: National Highway Traffic Safety Administration iconexternal icon
  2. National Academies of Sciences, Engineering, and Medicine. (2018). Getting to zero alcohol-impaired driving fatalities: A comprehensive approach to a persistent problem. Washington, DC: The National Academies Press. icon
  3. Sanem, J. R., Erickson, D. J., Rutledge, P. C., Lenk, K. M., Nelson, T. F., Jones-Webb, R., & Toomey, T. L. (2015). Association between alcohol-impaired driving enforcement-related strategies and alcohol-impaired driving. Accident Analysis & Prevention, 78, 104–109. icon
  4. Creaser, J. I., Aflleje, W., & Nardi, F. (2007). Evaluation of Minnesota’s Operation NightCAP program (MN/RC 2007-29). HumanFIRST Program, ITS Institute, University of Minnesota iconexternal icon
  5. Fell, J., Langston, E. A., Lacey, J. H., & Tippetts, A. S. (2008). Evaluation of seven publicized enforcement demonstration programs to reduce impaired driving: Georgia, Louisiana, Pennsylvania, Tennessee, Texas, Indiana, and Michigan (Report No. DOT HS 810 941). Washington, DC: National Highway Traffic Safety Administration iconexternal icon
  6. Morrison, C. N., Ferris, J., Wiebe, D. J., Peek-Asa, C., & Branas, C. C. (2019). Sobriety checkpoints and alcohol-involved motor vehicle crashes at different temporal scales. American Journal of Preventive Medicine, 56(6), 795–802. icon
  7. Erickson, D. J., Farbakhsh, K., Toomey, T. L., Lenk, K. M., Jones-Webb, R., & Nelson, T. F. (2015). Enforcement of alcohol-impaired driving laws in the United States: A national survey of state and local agencies. Traffic Injury Prevention, 16(6), 533–539. icon
  8. Eichelberger, A. H., & McCartt, A. T. (2016). Impaired driving enforcement practices among state and local law enforcement agencies in the United States. Journal of Safety Research, 58, 41–47. icon
  9. Fell, J., McKnight, A. S., & Auld-Owens, A. (2013). Increasing impaired-driving enforcement visibility: Six case studies. (Report No. DOT HS 811 716). Washington, DC: National Highway Traffic Safety Administration iconexternal icon
  10. Hedlund, J., & McCartt, A. (2002). Drunk driving: Seeking additional solutions. Washington, DC: AAA Foundation for Traffic Safety iconexternal icon.
  11. Greene, J. (2003). Battling DUI: A comparative analysis of checkpoints and saturation patrols. FBI Law Enforcement Bullletin, 72(1), 1–6. icon