Traffic Light graphic Traffic Tech
NHTSA - People Saving People Technology Transfer Series
Number 229 August 2000


Sixteen to twenty year-olds have the highest risk of being killed in a traffic crash of any age group. In fact, in 1998, motor vehicle crashes were the leading cause of death for young people of these ages. When alcohol is added, more 18-year-olds died in alcohol-related crashes where the blood alcohol concentration (BAC) was between .01 to .09 BAC than any other age.

Zero tolerance laws for youth address this problem directly by prohibiting driving by youth with any alcohol in their system. As of June 1998, all states and the District of Columbia had set a BAC limit of .02 or lower for drivers under the age of 21. The exact limit varies by state.

Mid-America Research Institute conducted a study for the National Highway Traffic Safety Administration (NHTSA) to examine the effectiveness of zero tolerance laws in four states: Florida, Maine, Oregon, and Texas.

It was expected that the effectiveness of the laws would vary between states depending on how long the law had been in place, the amount of associated publicity, the level of enforcement, as well as the sanctions imposed. The project also examined any difficulties in enforcing the law and unintended consequences that might arise because of the law.

Reductions in Single Vehicle Nighttime Injury Crashes

In both Maine and Oregon, which have longstanding zero tolerance laws, the volume of enforcement actions for zero tolerance violations approximated the rate for adult driving while intoxicated (DWI). In Maine, where the permissible BAC level was reduced from .02 to .00, there was a reduction in nighttime single vehicle injury (NSVI) crashes involving drivers under the age of 21 on the order of 36 percent. In Oregon, where a change in the age for the .00 limit was made from 18 to 21, there was a 40 percent reduction in nighttime single vehicle injury crashes. This particular type of crash is often used as a surrogate measure for alcohol-involved crashes.

In Florida and Texas, both with newer laws, there were little or no reductions in NSVI crashes. Florida showed a 5 percent reduction in NSVI crashes, and no change was observed in Texas. The enforcement levels in these two states seems to be rising gradually, however, which may lead to reductions in coming years.

Zero Tolerance Law License Suspension Rate and Reduction in Nighttime Single Vehicle Injury Crashes in Four States

State Zero Tolerance
Suspension Rate
Observed Reduction
in Nighttime Single
Vehicle Injury Crashes
Florida 0.12% 5%
Maine 1.75% 36%
Oregon 1.08% 40%
Texas 0.87% none

Law Enforcement Reaction

Discussions were conducted with law enforcement officers in all four states. According to the officers, passive alcohol sensors are rarely used in detecting zero tolerance violators in their states. In fact, they essentially were not used at all in Florida and Maine.

An issue that is sometimes raised about zero tolerance laws is that special provisions must be made for minors held in custody and that this is a disincentive for officers to enforce the law. Though a few officers raised this issue as a problem, the vast majority of those contacted said that notifying a parent or guardian is just a routine part of enforcement actions with youth and, from a law enforcement point of view, seldom present actual difficulties.

In general, officers were supportive of having an administrative track for zero tolerance violations rather than a criminal track. This approach seemed to work more smoothly overall, and resulted in fewer appeals of license suspensions and fewer requests for hardship licenses than by adult offenders.

Officers also said that a .00 BAC limit is preferable to .02 because it sends a clearer message to youth that no consumption of alcohol is legally compatible with driving.



For a copy of Zero Tolerance Laws for Youth: Four States' Experience (48 pages plus appendices) write to the Office of Research and Traffic Records, NHTSA, NTS-31, 400 Seventh Street, S.W., Washington, DC 20590, or send a fax to

(202) 366-7096. Amy Berning was the contract manager for this project.

U.S. Department
of Transportation
National Highway
Traffic Safety

400 Seventh Street, S.W. NTS-31
Washington, DC 20590

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