State BAC Limits .08 BAC Law Enacted Before 2001 .08 BAC Law Enacted in 2001 .08 BAC Law Not Enacted

The BAC limit of .10 percent that currently exists in many U.S. states is among the highest in the world. The limits in other countries range from zero (Czech Republic) to .08 percent. There are consequences attached to setting a BAC limit so high that a 180-pound man can drink five bottles of beer and still be under the legal limit.

Laboratory studies have found that some basic skills required for driving start to deteriorate at BACs below .02 percent. At this level, drivers have attention problems such as staying in their lane while watching for other cars and pedestrians. By the time BACs reach .08 percent, most driving skills are seriously impaired.

Studies of actual crashes point to similar effects. Starting from levels as low as .02 percent BAC, the chances of being involved in a crash steadily rise as BAC increases. As BAC rises above .08 percent, a driver's risk of being involved in a fatal crash increases from 11 to 52 times that for a sober driver. The evidence clearly indicates that people with BACs of .08 percent and above don't drive as well as sober people and that they have a much greater chance of being involved in a crash.

But do laws that reduce the BAC limit to .08 percent actually save lives? To address this question, scientists at the Centers for Disease Control and Prevention reviewed and integrated existing U.S. research that assessed the impact of changing the BAC limit from .10 percent to .08 percent. Our review combined the results of nine studies covering 16 states that had lowered their BACs to .08 percent.

The law's change was consistently associated with a lower level of alcohol-related crashes. On average, deaths from alcohol-related crashes dropped seven percent after .08 percent BAC laws were adopted.

It is estimated if all 50 states had .08 percent BAC laws, 300 to 500 lives would be saved annually. It is likely that many more serious injuries would also be prevented.

The effects of the lower BAC laws were not limited to drivers with BACs in the .08 percent to .10 percent range. Several studies found that deaths among drinking drivers with BACs of .10 percent and higher declined by about the same amount as for those with lower BACs.

The one study that looked at fatal crashes involving drivers with BACs of .15 percent and higher also found similar results. It seems that even these drivers, who may be hard-core drinkers, are deterred by the law change.

Based on the results of this review, the independent Task Force on Community Preventive Services strongly recommended that states adopt .08 percent BAC laws to help reduce deaths resulting from drinking and driving. This recommendation echoes one made more than a decade ago in the U.S. Surgeon General's Report on Drinking and Driving.

These recommendations for .08 percent BAC laws were recently put into practice by the Fiscal Year 2001 Department of Transportation and Related Agencies Appropriations Act. The Act requires states to adopt .08 percent BAC laws by October 2003 or lose a portion of highway funds. Since the passage of this bill, nine states have made the change, bringing the total number of states with .08 percent BAC laws to 28.

Implementing .08 percent BAC laws is only one step in the fight against drinking and driving. Continued progress will require concerted efforts on two fronts - research on the effectiveness of other interventions and policies to reduce drinking and driving, and a commitment to putting prevention into practice at the state and local level.