Table 6. Effects of changing the mimiumum legal drinking age: summary effects from the body of evidence on crash outcomes likely to involve alcohol

OutcomeNumber of studiesMedian changeRangea
Raising the MLDA
Fatal injury crashesb936,37,39,41,43-46,50 17% decrease30%-7% decrease
Fatal and nonfatal injury crashes442,48,51,52 15% decrease33%-6% decrease
Other crashes240,52 NA21% and 18% decrease
Lowering the MLDA
Fatal injury crashes353,54,55 8% increase2%-38% increase
Fatal and nonfatal injury crashes460 5% increase2% decrease to 22% increase
Other crashes256,58 NA22% and 186% increase
Estimated effect of raising the MLDA by 3 years (from 18 to 21) from regression-based studies29,64-80
Fatalities and fatal crashes930,61,65-68,73-75 12% decrease17%-8% decrease

When 7 or more studies were available, an interquartile range is presented.


A study evaluating fatal crashes among 16- and 17-year-olds47 was not included in the summary effect measures.

MLDA, minimum legal drinking age; NA, not applicable.

From: Reviews of Evidence Regarding Interventions to Reduce Alcohol-Impaired Driving

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