Saturation Patrols

A saturation patrol (also called a blanket patrol, “wolf pack,” or dedicated DWI patrol) consists of a large number of law enforcement officers patrolling a specific area for a set time to increase visibility of enforcement. (UNC Highway Safety Research Center, 2011, p. 1-20)

Saturation patrols look for impaired-driving behaviors, such as reckless or aggressive driving, speeding, and following too closely. “Like sobriety checkpoints, the primary purpose of saturation patrols is to deter driving after drinking by increasing the perceived risk of arrest. To do this, saturation patrols should be publicized extensively and conducted regularly” (UNC Highway Safety Research Center, 2011, p. 1-20). Saturation patrols can have advantages over sobriety checkpoints, including increased effectiveness, reduced staffing, and comparative ease of operation (Greene, 2003).

A less-intensive strategy is the “roving patrol” in which individual patrol officers concentrate on detecting and arresting impaired drivers in an area where impaired driving is common or where alcohol-involved crashes have occurred (Stuster, 2000). A “how-to” guide for planning and publicizing saturation patrols and sobriety checkpoints is available from NHTSA (NHTSA, 2002). (UNC Highway Safety Research Center, 2011, p. 1-20)


Saturation patrols have been used by law enforcement agencies longer than sobriety checkpoints (Greene, 2003). The first high-profile saturation patrol, Project Zero Patrol, was developed as New York State’s Zone Enforcement Reduction Operation in the late 1990s (National Hardcore Drunk Driver Project, 1998). The Project Zero Patrol, a statewide saturation patrol initiative that combined resources across state and local police and sheriff departments, proved effective at deterring impaired driving. Other states have since adopted similar saturation patrol programs, such as Minnesota’s Operation Nighttime Concentrated Alcohol Patrol (NightCAP) program, which has doubled the annual number of stops and citations since its implementation in 2003.


“A survey conducted by The Century Council (2008) reported that 44 States used saturation patrols”; however, it did not report which states. They are legal in all states (National Hardcore Drunk Driver Project, 1998). We were unable to identify a list of states that actively use saturation patrols.


A demonstration program in Michigan revealed that saturation patrols can be effective in reducing alcohol-related fatal crashes when accompanied by intensive publicity ([Fell, Langston, et al., 2008]). Michigan is prohibited by State law from conducting sobriety checkpoints. In addition, saturation patrols can be very effective in arresting impaired drivers. For example, in 2006 Minnesota’s 290 saturation patrols stopped 33,923 vehicles and arrested 2,796 impaired drivers ([National Hardcore Drunk Driver Project, 1998]). (UNC Highway Safety Research Center, 2011, p. 1-20)

Saturation patrols have also been found to promote other safe driving behavior, such as seat belt usage (Hedlund, Gilbert, et al., 2008).

Recent Research on Effectiveness


Measuring Effectiveness

Effectiveness can be measured in DWI arrests per working hour. Other measures can include the number of drivers evaluated and the number of DWI arrests per patrol. Because saturation points are intended to deter impaired driving, an appropriate measure would be the number of impaired drivers deterred, but this is not easily identified. Instead, traffic enforcement agencies can track changes in annual arrest rates and alcohol-related crashes before and after the introduction of saturation patrols.


The main costs are for law enforcement time and for publicity. Saturation patrol operations are quite flexible in both the number of officers required and the time that each officer participates in the patrol. As with sobriety checkpoints, publicity can be costly if paid media is used. (UNC Highway Safety Research Center, 2011, p. 1-20)

In order to be most effective, saturation patrols need to be frequent and heavily advertised.

Time to Implement

Saturation patrols can be implemented within three months if officers are trained in detecting impaired drivers and in SFST. See NHTSA (2002) for implementation information. (UNC Highway Safety Research Center, 2011, p. 1-20)

Other Issues


“Saturation patrols are legal in all jurisdictions” (UNC Highway Safety Research Center, 2011, p. 1-20).


As with sobriety checkpoints, saturation patrols should be highly visible and publicized extensively to be effective in deterring impaired driving. Communication and enforcement plans should be coordinated. Messages should clearly and unambiguously support enforcement. Paid media may be necessary to complement news stories and other earned media, especially in a continuing saturation patrol program ([Goodwin, Foss, et al., 2005], Strategy B1). (UNC Highway Safety Research Center, 2011, p. 1-20)

Other Offenses

“Saturation patrols are effective in detecting other driving and criminal offenses” (UNC Highway Safety Research Center, 2011, p. 1-20).