State Alcohol Estimates |
|
The following data provide estimates of alcohol involvement in fatal crashes for the United States To address the missing data issue, NHTSA has developed and employs a statistical model to estimate the likelihood that a fatal crash-involved driver or nonoccupant was sober, had some alcohol, or was intoxicated at the time of the crash. The statistical model is based on important characteristics of the crash including crash factors (e.g., time of day, day of week, type of crash, location), vehicle factors (e.g., vehicle type and role in the crash), and person factors (e.g., age, sex, restraint use, previous driving violations), and whether or not the State had a 21-year-old minimum drinking age law. The statistical model was developed using all available known data in the aggregate (that is, at the national level) and applied to each individual driver and nonoccupant with an unknown BAC test result. The estimates presented include a mix of both known and estimated BACs. A motor vehicle crash is considered to be alcohol-related if at least one driver or nonoccupant (such as a pedestrian or pedalcyclist) involved in the crash is determined to have had a BAC of .01 gram per deciliter (g/dL) or higher. Thus, any fatality that occurs in an alcohol-related crash is considered an alcohol-related fatality. The term “alcohol-related” does not indicate that a crash or fatality was caused by the presence of alcohol. Great caution should be exercised in comparing the levels of alcohol involvement among States. Differences in alcohol involvement can be due to any number of factors not necessarily directly related to a State’s alcohol traffic safety program. Factors affecting alcohol involvement in fatal crashes include:
One of the major differences among States is in the degree of testing for driver and nonoccupant BACs. These differences in testing affect the accuracy and reliability of the estimates presented, and for 2005 range from a low of 8 percent known BACs to a high of 82 percent known BACs. States with higher rates of known BACs yield estimates of fatal crash alcohol involvement with greater accuracy and precision. Estimates of Alcohol-Involved Fatalities The following tables estimate alcohol involvement for the Nation and on a State-by-State basis for 1982 and 2005 using NHTSA’s discriminant function model as applied to the FARS data. This model estimates BACs of drivers and nonoccupants when their BAC is not available. A driver or nonoccupant involved is considered alcohol-related if he/she is involved in the fatal crash and exhibits a BAC of .01 or greater (the last column on the right in the tables). A fatality is considered alcohol-related if any driver or nonoccupant involved in the crash had a positive BAC. Estimates are presented for four categories:
Nationwide in 2005, alcohol was involved in 39 percent of the traffic fatalities (BAC .01-.07, 5 percent; BAC .08 or greater, 33 percent), translating to 16,885 alcohol-related fatalities. Table 1 - Fatalities by Highest Blood Alcohol Concentration (BAC) in the Crash, 1982 Table 2 - Fatalities by Highest Blood Alcohol Concentration (BAC) in the Crash, 2005 Estimates of Alcohol-Involved Drivers The following tables estimate alcohol involvement for the Nation and on a State-by-State basis for 1982 and 2005 using NHTSA’s discriminant function model as applied to the FARS data. This model estimates BACs of drivers and nonoccupants when their BAC is not available. The estimates presented represent the combination of known and estimated BACs. A driver or nonoccupant involved is considered alcohol-related if he/she is involved in the fatal crash and exhibits a BAC of .01 or greater (the last column on the right in the tables). Estimates are presented for four categories:
Nationwide in 2005, alcohol was present in 24 percent of the drivers involved in fatal crashes (BAC .01-.07, 4 percent; BAC .08 or greater, 20 percent). Table 3 - Drivers Involved in Fatal Crashes by Blood Alcohol Concentration (BAC) of the Driver, 1982 Table 4 - Drivers Involved in Fatal Crashes by Blood Alcohol Concentration (BAC) of the Driver, 2005 Availability of Known BAC Test Results The following tables present the percentage of drivers and nonoccupants involved in fatal crashes where a BAC test was given and the results were in the FARS file. Individual tables are presented for all drivers/nonoccupants, fatally injured drivers and surviving drivers. Nationwide in 2005, a total of 17,581 fatally injured drivers had BAC test results out of a total of 27,472, or 64 percent. For surviving drivers, BAC test results were known on 7,471 out of 31,632 drivers, or 24 percent. Overall in 2005, FARS contained BAC test results on a total of 25,052 drivers out of 59,104 involved in fatal crashes, or 42 percent. Statistics for the base year 1982 are also presented. Any individual State proportion greater than the national percentage is considered good. The higher the proportion of drivers with known BAC test results, the more reliable the State estimate. Table 5 - Driver Fatalities by State and Blood Alcohol Concentration (BAC) Test Status, 1982 Table 6 - Driver Fatalities by State and Blood Alcohol Concentration (BAC) Test Status, 2005 Table 7 - Surviving Drivers by State and Blood Alcohol Concentration (BAC) Test Status, 1982 Table 8 - Surviving Drivers by State and Blood Alcohol Concentration (BAC) Test Status, 2005 Table 9 - Blood Alcohol Concentration (BAC) Test Status for Drivers, Pedestrians, and Pedalcyclists Involved in Fatal Traffic Crashes, 1982 and 2005 State-Level Estimates on a Regional Basis For the States in the various NHTSA regions, the following table summarizes the estimated percentages of fatalities that were alcohol-related (BAC of .01 or greater) in 1982 and 2005 and the estimated percentage of drivers involved in fatal crashes with BAC of .08 or greater. Table 10 - Estimated Percent Alcohol-Related Fatalities and Drivers With BAC .08 or Greater in Fatal Crashes by Region and State, 1982 and 2005
|