Enforcement against service of alcohol to inoxicated patrons

Contact name: 
A. James McKnight
Principal Investigator
Pacific Institute for Research and Evaluation
78 Farragut Rd, Annapolis MD 21403, USA



Of drivers killed in highway crashes close to a third were impaired by alcohol. Although service to intoxicated patrons is prohibited by law in all states, from a third to a half of intoxicated drivers consume their last drink at a licensed establishment.


An intervention was developed to reduce the service of alcohol to intoxicated patrons of licensed establishments.


Undercover police officers were sent in to establishments to enforce refusal of service to visibly intoxicated patrons, as required by state and local law throughout the U.S.


Enforcement of the law achieved a 40% reduction in service to pseudopatrons exhibiting signs of intoxication as well as a 25% reduction in the proportion of intoxicated drivers consuming alcohol at licensed establishments.


Enforcement of laws prohibiting service of alcohol to intoxicated patrons of licensed establishments provides one, and probably the only, means of reducing alcohol impaired driving.

Intervention details

Type of intervention
Problem addressed
Alcohol, Impaired driving
Intervention setting
Target population

Servers in licensed establishments serving alcoholic beverages to "visibly intoxicated" patrons.

Substances adressed
Strategic target group (social agents acting as intermediaries between intervention and target group)

Focus upon greatest sources of arrested DWIs (Driving While Intoxicated).

Intervention activities
Undercover Alcoholic Beveridge Control (ABC)
Legislative measures
Nightlife management
Stricter enforcement
Enforcement visits to each licensed establishment from one to three times a year depending on numbers of patrons arrested for DWI.
Theory/evidence behind the intervention

Based upon the need for enforcement to achieve compliance with any law.

Number of people needed
The needed level of enforcement can be acheived by allocating two person weeks of enforcement by undercover Alcoholic Beverage Control officers in each city.
Specific training required?
Time required to run
Two person weeks per year are sufficient.
Other resource requirements


Evaluation details

Evaluation type (e.g. process, outcome, cost-effectiveness)
Process, outcome & cost-effectiveness
Activities evaluated

Enforcement visits to each licensed establishment and instruction in identitifying signs of intoxication.

Type of evaluator (e.g. external consultant, internal evaluator)
Internal evaluator
Evaluation results (Process evaluation)

The evaluation showed a 40% greater reduction in service to pseudo patrons and a 25% greater reduction in arrested DWIs from licensed establishments

Evaluation results (Outcome evaluation)

The oucome showed the intervention as capable of reducing alcohol impaired driving, which reduces the prospect of injury and death both to those consuming alcoholic beverages at licensed establishments and to drivers with whom they share the road.

Evaluation results (Cost effectiveness)

A cost-benefit analysis showed a net benefit to the public of $90 per dollar of enforcement. A problem that is often overlooked in such analyses is that the benefit is realized by the public and doesn't help to defray the cost born by enforcement agencies.

Evaluation results (Other)

An attempt to overcome the problem just described has been to design the enforcement intervention in a way that allows it to be implemented by transfering 50 hours per year of current staff time from other duties to enforcement, with no increase in cost to ABC agencies. A proposal to evaluate such an intervention has been forwarded to NIAAA (National Institute on Alcohol Abuse and Alcoholism).

Evaluation references

McKnight, A. J., & Streff, F. M. (1994). The effect of enforcement upon service of alcohol to intoxicated patrons of bars and restaurants. Accident Analysis and Prevention, 26(1), 79-88.

An abstract for this journal article can be found in the HNT literature section here.