Most states don't conduct sobriety checkpoints frequently, even though this enforcement method deters alcohol-impaired driving and reduces crashes. Thirty-seven states and the District of Columbia conduct checkpoints, but only 11 states conduct them as often as once a week.
"Sobriety checkpoints probably are the most effective enforcement strategy we can use against alcohol-impaired driving," says survey leader James Fell, director of traffic safety and enforcement programs at the Pacific Institute for Research and Evaluation. He adds that "if checkpoints are conducted routinely in a community — that is, on a weekly basis — they can result in a 20 percent reduction in alcohol-related fatal crashes." This finding is from a statewide study of Tennessee's checkpoint program (see "Sobriety checkpoints reduce crash deaths on Tennessee roads ," June 19, 1999).
Not all states conduct checkpoints. State laws prohibit them in nine states, and in four others checkpoints aren't conducted either because the laws are subject to interpretation or because of policy issues.
In some of the remaining 37 states and the District of Columbia, the question is why sobriety checkpoints aren't conducted more often. To find out, Fell compared five states where checkpoints are relatively frequent (Georgia, Indiana, New York, Nevada, and Virginia) and five states where they aren't (Alabama, Arizona, Illinois, Maryland, and Ohio).
In the first group of states, enforcement officials generally have community support from DWI task forces and pressure from citizen groups such as Mothers Against Drunk Driving (MADD). Such support appears to be a key factor in whether and how often checkpoints are conducted. States where there are few of them usually don't have active task forces, and officials don't feel pressured to conduct more checkpoints. Officials in some of these states say checkpoints aren't conducted more frequently because police view regular patrols as more productive.
"There's a perception that checkpoints are less effective than other enforcement strategies because they don't yield as many arrests. But that's missing the point," explains Susan Ferguson, the Institute's senior vice president for research. "Checkpoints are more likely to prevent the offense in the first place."
Another factor involves police resources. States with less frequent checkpoints often use 15 to 30 or more officers, which increases the cost and complicates the logistics. States with frequent checkpoints tend to use only 2 to 15 officers.
"You don't need 20 or 30 officers. You just need enough to take care of any safety issues," Fell says. Research has shown that as few as 2 to 5 officers can handle a checkpoint without any loss of effectiveness.
Minimizing the use of police resources is one way costs could be controlled even as sobriety checkpoints are conducted more frequently. Still, officials in all 10 states included in Fell's study say funding is an issue and more federal support would help them conduct checkpoints more often. Federal grants are available for this, and states with frequent checkpoints are more likely to use all available funds from federal, state, and local sources.