Sobriety Checkpoints

A sobriety checkpoint is a predetermined location at which

law enforcement officers stop vehicles at a predetermined location to check whether the driver is impaired. They either stop every vehicle or stop vehicles at some regular interval, such as every third or tenth vehicle. The purpose of checkpoints is to deter driving after drinking by increasing the perceived risk of arrest. To do this, checkpoints should be highly visible, publicized extensively, and conducted regularly. Fell, Lacey, and Voas (2004) provide an overview of checkpoint operations, use, effectiveness, and issues. (UNC Highway Safety Research Center, 2011, p. 1-18)

History

Sobriety checkpoints were first introduced in Scandinavia in the 1930s (Elder, Shults, et al., 2002) and became common in the United States in the early 1980s (Hedlund and McCartt, 2002). In 1990, the U.S. Supreme Court ruled in favor of the constitutionality of sobriety checkpoints; however, the debate over checkpoints has continued, and some individual state courts have deemed them illegal for violating state constitutions (IIHS, 2012).

Use

Sobriety checkpoints are authorized in 38 States and the District of Columbia (NHTSA, [2008g] [see Table B.3]), but few States conduct them often. According to GHSA ([2014b]), only 13 States conduct checkpoints on a weekly basis. The main reasons checkpoints are not used more frequently are lack of law enforcement personnel and lack of funding ([Fell, Ferguson, et al., 2003]). (UNC Highway Safety Research Center, 2011, p. 1-18)

Effectiveness

CDC’s systematic review of 11 high-quality studies found that checkpoints reduced alcohol-related fatal, injury, and property damage crashes each by about 20 percent ([Elder, Shults, et al., 2002]). Similarly, a meta-analysis found that checkpoints reduce alcohol-related crashes by 17 percent, and all crashes by 10 to 15 percent ([Erke, Goldenbeld, and Vaa, 2009]). In recent years, NHTSA has supported a number of efforts to reduce alcohol-impaired driving using sobriety checkpoints. Evaluations of recent statewide campaigns in Connecticut and West Virginia involving sobriety checkpoints and extensive paid media found decreases in alcohol-related fatalities following the program, as well as fewer drivers with positive BACs at roadside surveys ([Zwicker, Chaudhary, Maloney, et al., 2007]; [Zwicker, Chaudhary, Solomon, et al., 2007]). In addition, a study examining demonstration programs in 7 States found reductions in alcohol-related fatalities between 11 and 20 percent in States that employed numerous checkpoints or other highly visible impaired driving enforcement operations and intensive publicity of the enforcement activities, including paid advertising ([Fell, Langston, et al., 2008]). States with lower levels of enforcement and publicity did not demonstrate a decrease in fatalities relative to neighboring States. See also NHTSA’s Strategic Evaluation States initiative (NHTSA, [2007]; Syner et al., 2008), the Checkpoint Strikeforce program ([Lacey, Kelley-Baker, et al., 2008]), and the national Labor Day holiday campaign: Drunk Driving. Over the Limit. Under Arrest ([Solomon, Hedlund, et al., 2008]). (UNC Highway Safety Research Center, 2011, p. 1-18)

Recent Research on Effectiveness

Nunn and Newby, 2011, examined the effectiveness of 22 sobriety checkpoints implemented over one year at nine checkpoint locations in Indianapolis, Indiana, using various methodologies (pre/post, difference in differences, and interrupted time series). Impairment rates (impaired-driver collisions per 100 collisions) decreased insignificantly in nondowntown locations and increased significantly in downtown areas. Sobriety checkpoints also resulted in a small significant reduction in the number of alcohol-related crashes when compared with similar control locations, with differences more pronounced in downtown areas. Finally, the time-series analysis found that the number of impaired collisions in postcheckpoint periods was approximately 19 percent less than in the precheckpoint periods.

Measuring Effectiveness

Because sobriety checkpoints 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 track changes in alcohol-related crashes, injuries, and fatalities. Measures can also include the number of stops and the number of DWI arrests per checkpoint or awareness or perceptions of the checkpoints obtained through surveys.

Costs

The main costs are for law enforcement time and for publicity. A typical checkpoint requires several hours from each law enforcement officer involved. Law enforcement costs can be reduced by operating checkpoints with 3 to 5 officers, perhaps supplemented by volunteers, instead of the 10 to 12 or more officers used in some jurisdictions (NHTSA, 2002; NHTSA, [2006a]; [Stuster and Blowers, 1995]). Law enforcement agencies in two rural West Virginia counties were able to sustain a year-long program of weekly low-staff checkpoints. The proportion of nighttime drivers with BACs of .05 and higher was 70 percent lower in these counties compared to drivers in comparison counties that did not operate additional checkpoints ([Lacey, Ferguson, et al., 2006]). NHTSA has a guidebook available to assist law enforcement agencies in planning, operating and evaluating low-staff sobriety checkpoints (NHTSA, [2006a]). (UNC Highway Safety Research Center, 2011, pp. 1-18–1-19)

“Checkpoint publicity can be costly if paid media are used, although publicity can also include earned media” (e.g., free news coverage of campaign) (UNC Highway Safety Research Center, 2011, p. 1-19).

Time to Implement

“Checkpoints can be implemented very quickly if officers are trained in detecting impaired drivers, SFST [Standardized Field Sobriety Test], and checkpoint operational procedures. See NHTSA, 2002, for implementation information” (UNC Highway Safety Research Center, 2011, p. 1-19).

Other Issues

Legality

Checkpoints currently are permitted in 38 States and the District of Columbia (NHTSA, [2008g]). Checkpoints are permitted under the United States Constitution but some State courts have held that checkpoints violate their State’s constitution. Some State legislatures have not authorized checkpoints. States where checkpoints are not permitted may use saturation patrols (see [“Saturation Patrols,” next]). (UNC Highway Safety Research Center, 2011, p. 1-19)

Visibility

According to NHTSA, checkpoints

must be highly visible and publicized extensively to be effective [(NHTSA, 2011b)]. 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 checkpoint program ([Goodwin, Foss, et al., 2005], Strategy B1). (UNC Highway Safety Research Center, 2011, p. 1-19)

Arrests

The primary purpose of checkpoints is to deter impaired driving, not to increase arrests. Police generally arrest impaired drivers detected at checkpoints and publicize those arrests, but arrests at checkpoints should not be used as a measure of checkpoint effectiveness. The number of drivers evaluated at checkpoints would be a more appropriate measure.

Other Offenses

Checkpoints may also be used to check for valid driver’s licenses, seat belt use, outstanding warrants, stolen vehicles, and other traffic and criminal infractions.

Combining Checkpoints with Other Activities

To enhance the visibility of their law enforcement operations, some jurisdictions combine checkpoints with other activities, such as saturation patrols. For example, some law enforcement agencies conduct both checkpoints and saturation patrols during the same weekend. Others alternate checkpoints and saturation patrols on different weekends as part of a larger impaired-driving enforcement effort.

Table B.3. State Laws on Sobriety Checkpoints, as of December 2011

State	Checkpoints Conducted	Frequency	Legality
Ala.	Yes	Throughout the year	Upheld under U.S. Constitution
Alaska	No	Not applicable	No state authority
Ariz.	Yes	At least once per month	Upheld under U.S. Constitution
Ark.	Yes	Weekly	Upheld under state and U.S. Constitutions
Calif.	Yes	2,500+ annually	Upheld under state and U.S. Constitutions
Colo.	Yes	Once or twice per month	Upheld under state and U.S. Constitutions
Conn.	Yes	Not applicable	Upheld under state constitution
D.C.	Yes	Monthly January to June; weekly July through December	Upheld under state law and U.S. Constitution
Del.	Yes	Once or twice per month	Upheld under U.S. Constitution
Fla.	Yes	Between 15 and 20 per month	Upheld under U.S. Constitution
Ga.	Yes	Weekly	Upheld under state and U.S. Constitutions
Hawaii	Yes	Weekly	Authorized by statute
Idaho	No	Not applicable	Illegal under state law
Ill.	Yes	Several hundred per year	Upheld under U.S. Constitution
Ind.	Yes	Not applicable	Upheld under state constitution
Iowa	No	Not applicable	Not permitted; statute authorizing roadblock controls does not authorize sobriety checkpoints
Kan.	Yes	Once or twice per month	Upheld under state law and U.S. Constitution
Ky.	Yes	Weekly	Upheld under U.S. Constitution
La.	Yes	Not applicable	Upheld under state constitution
Maine	Yes	Not applicable	Upheld under U.S. Constitution
Md.	Yes	Weekly	Upheld under state and U.S. Constitutions
Mass.	Yes	Year round	Upheld under state and U.S. Constitutions
Mich.	No	Not applicable	Illegal under state constitution
Minn.	No	Not applicable	Illegal under state constitution
Miss.	Yes	Weekly	Upheld under U.S. Constitution
Mo.	Yes	Once or twice per month	Upheld under state and U.S. Constitution
Mont.	No	Not applicable	Statute permits only safety spot checks
Neb.	Yes	6 to 10 per month	Upheld under state law
Nev.	Yes	Once or twice per month	Authorized by statute
N.H.	Yes	Weekly, weather permitting	Authorized by statute (must be judicially approved)
N.J.	Yes	Once or twice per month	Upheld under state and U.S. Constitutions
N.M.	Yes	Not applicable	Upheld under state and U.S. Constitutions (law enforcement must follow guidelines)
N.Y.	Yes	Weekly	Upheld under U.S. Constitution
N.C.	Yes	Weekly	Authorized by statute
N.D.	Yes	Not applicable	Upheld under state and U.S. Constitutions
Ohio	Yes	Year round	Upheld under state and U.S. Constitutions
Okla.	Yes	Once or twice per month	Upheld under state and U.S. Constitutions
Ore.	No	Not applicable	Illegal under state constitution
Pa.	Yes	Several hundred per year	Upheld under state and U.S. Constitutions
R.I.	No	Not applicable	Illegal under state constitution
S.C.	Yes	Not applicable	No state authority
S.D.	Yes	Weekly	Upheld under state and U.S. Constitutions
Tenn.	Yes	Once or twice per month	Upheld under state and U.S. Constitutions
Texas	No	Not applicable	Illegal under Texas’ interpretation of U.S. Constitution
Utah	Yes	About every other month	Authorized by statute
Vt.	Yes	Weekly	Upheld under state and U.S. Constitutions
Va.	Yes	Weekly	Upheld under state and U.S. Constitutions
Wash.	No	Not applicable	Illegal under state constitution
W.Va.	Yes	Weekly	Upheld under state and U.S. Constitutions
Wis.	No	Not applicable	Prohibited by statute
Wyo.	No	Not applicable	Prohibited by interpretation of roadblock statute

SOURCE: GHSA, 2014b.