|Users Guide| Methods and Definitions Fact Sheet| <Impaired Driving in the United States|
(See the Users Guide for a more detailed description of the methods used)
Police-reported counts of impaired-driving crashes were obtained from State departments of transportation, highway safety, or highway patrol. The data year varies according to the most recent data available during the collection period unless data from the previous year were more complete. Only one year’s data are reflected in each State’s cost estimates. The year is identified in the first sentence of each State cost fact sheet.
Fatality counts for 1996 through 2000 by blood alcohol concentration (BAC) came from NHTSA’s Fatality Analysis Reporting System (FARS). The U.S. fact sheet uses 2000 FARS data from NHTSA’s new multiple imputation method. The individual State, District of Colombia, and Puerto Rico fact sheets use FARS numbers from NHTSA’s old method, because that was what was available when they were prepared. Police under-reporting of alcohol-involvement in crashes is well documented. Police reported counts of impaired-driving injury crashes were adjusted for under-reporting according to the methods in Blincoe, Seay et al. (2002). Incidence of property damage only crashes was estimated from the ratio of property damage only alcohol-related crashes to injury crashes from Blincoe, Seay et al. (2002). Alcohol-related deaths, injuries, and crashes were distributed by BAC using the methods in Miller, Lestina, and Spicer (1998). Alcohol-involvement rates decline with crash severity; effectiveness should be expected to vary as well as severity as a lesser percentage of crashes are affected by alcohol.
In some jurisdictions, police do not report alcohol involvement in non-fatal incidents or police counts could not be accessed. For the District of Columbia, Illinois, and Rhode Island, alcohol-related crash counts were estimated with a regression that had two explanatory variables – (1) alcohol-related fatal crashes and (2) vehicle miles traveled in urban areas. For Colorado, the District of Columbia, Illinois, Louisiana, Massachusetts, North Dakota, and Rhode Island, alcohol-related injury counts were estimated with a regression that had two explanatory variables – (1) total alcohol-related crashes and (2) the product of the % of crash deaths that were alcohol-related times total injuries. In both regressions, all coefficients were statistically significant at the 95% confidence level. The regressions explained more than 80% of the variance in the crash and injury counts for the States with data. Total crash injuries came from the State or from 1996 and 1997 Highway Statistics (Federal Highway Administration 1997, 1998).
Cost per alcohol-related fatality, injury, and crash, as well as sources of payment, were calculated by the methods in Blincoe, Seay et al. (2002) and Zaloshnja et al. (2001). The costs are NHTSA’s latest estimates. Future costs are converted to present value with a 4% discount rate. Crash costs per mile driven at various BACs were developed using methods in Miller, Spicer, and Levy (1999). Costs per drink (a drink contains one-half ounce of alcohol) were obtained by dividing the State’s impaired-driving costs by its alcohol consumption in 1998 from Williams et al. (2000). Auto insurance losses attributable to impaired driving were the product of total auto insurance losses from Panko (2001) and the percentage of the State’s total motor-vehicle crash costs attributable to alcohol. External costs, the costs paid by people other than alcohol-impaired drivers, were computed by the methods in Levy and Miller (1995) and Blincoe (1996). All costs were adjusted to reflect State prices and wages with price adjusters from ACCRA (1998) and the Council of Economic Advisors (2001).
Miller (2001); Miller and Levy (1998, 2000); Miller, Galbraith and Lawrence (1998); Miller, Lestina and Spicer (1998); and Levy and Miller (1995) provided the basis for estimating the savings from alcohol strategies. They analyzed average national costs and impacts. We made State-specific price adjustments. Because impaired-driving rates differ by State, the benefits from prevention also will vary. To account for these differences, the benefits were adjusted by the ratio of alcohol-related crash costs per driver in the State versus the United States. Just adopting a legislative countermeasure does not mean it will achieve the average impact. It needs to be effectively implemented and well-publicized to have maximum effectiveness.
In the studies cited, the percentage reduction in alcohol-related crashes generally was estimated from evaluations of fatality impacts. None of the State estimates consider how differences in enforcement and other factors will cause effectiveness to vary between States. Sources of the effectiveness estimates were:
Interventions Targeting Repeat Offenders
Four alternative sanctioning approaches are important for decreasing recidivism. Analysis of FARS data shows that 8%–12% of fatal alcohol-related crashes involved recidivists. The analysis uses the 1999–2000 estimate from FARS that 9.35% of alcohol-related fatal crashes could potentially be affected by these countermeasures. In cases where only information about the reduction in recidivism was available, we assumed the reduction in impaired driving crashes of recidivists equaled their reduction in convictions.
Occupant Protection Measures
Definitions of Costs
Medical costs include hospital, physician, rehabilitation, prescription, and related payments. Coroner and premature burial costs for fatalities, and the costs of medically-related loss compensation through insurance and the courts are also included. Loss compensation omits time spent on the loss recovery process.
Other monetary costs include:
Work loss (lost productivity), which includes wages, fringe benefits, and household work lost by the injured, as well as the costs of productivity loss compensation. This category also includes productivity loss by those stuck in crash-related traffic jams and by co-workers and supervisors while recruiting and training replacements for disabled workers, investigating work-related crashes, and repairing damaged company vehicles. Excluded for lack of data are earnings lost by family and friends caring for injured adults and the value of schoolwork lost.
Public services costs of police, fire, ambulance, and helicopter services.
Property damage costs to repair or replace damaged vehicles and property including the costs of damage compensation.
Quality of life places a dollar value on the pain, suffering, and lost quality of life that victims and their families experience due to a death or injury.
To value the quality of life lost to fatal injuries, the starting point is to estimate the value people place on survival. The value of survival is measured from the amounts people spend (in dollars or time) for safety. About 75 technically sound "willingness to pay" studies have estimated this value (Miller, 2000). They examine such things as markets for auto safety features and smoke detectors, extra wages paid to get workers to take risky jobs, and speed choice while driving.
The value of survival is essentially the combined value of future earnings and quality of life. The quality of life cost per death is obtained by subtracting the lost future earnings.
The quality of life lost to nonfatal injury was valued in two steps (Miller, Lestina, and Spicer 1998). In the first, physicians rated the typical effects of different injuries on six dimensions of functioning: mobility, cognitive, bending and grasping, pain, sensory, and cosmetic. Data were also collected about a seventh dimension: the ability to work. Using surveys about the value people place on different dimensions of functioning, the data were combined to obtain a percentage of the value of survival lost to each injury. Again, subtracting lost future earnings yielded the quality of life costs per injury.
Since 1989, the U.S. Office of Management and Budget (1989) has required all federal regulatory benefit-cost analyses to include quality of life costs if they place a dollar value on saving lives.
ACCRA. ACCRA Cost of Living Index, Louisville, KY, 1998.
Blincoe LJ. The Economic Cost of Motor Vehicle Crashes 1994, DOT HS 808425, Washington, DC: NHTSA, 1996.
Blincoe L, Seay A et al. The Economic Impact of Motor Vehicle Crashes 2000. Washington DC: NHTSA, 2002.
Centers for Disease Control and Prevention. Alcohol-related traffic fatalities involving children – United States, 1985-1996. Morbidity and Mortality Weekly Report, 46:1130-1133, 1997.
Council of Economic Advisors. Economic Report of the President, 2000, Washington, DC: U.S. Government Printing Office, 2001.
Dinh-Zarr TB, Sleet DA, Shults R, Zaza S, Elder RW, Nichols JL, Thompson RS, Sosin DM and the Task Force on Community Preventive Services. Reviews of evidence regarding interventions to increase the use of safety belts. American Journal of Prevention Medicine, 21(4):48-65, 2001.
Federal Highway Administration. Highway Statistics, 1996. Washington, DC: U.S. Department of Transportation, FHA, FHA-PL-98-003, 1997.
Federal Highway Administration. Highway Statistics, 1997. Washington, DC: U.S. Department of Transportation, FHA. [On-line]. Available: http://www.fhwa.dot.gov/ohim/hs97/hs97page.htm, 1998.
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Jones RG, Wiliszowski CH & Lacey JH. Evaluation of Alternative Programs for Repeat DWI Offenders. DOT HS 808 493. Washington, DC: NHTSA, 1996.
Klein TM. Changes in alcohol-involved fatal crashes associated with tougher state alcohol legislation. DTNH 22-88-C-07045. Washington, DC: NHTSA, Washington DC: NHTSA, 1989.
Lacey JH, Jones RK & Smith RG. Evaluation of checkpoint Tennessee: Tennessee’s statewide sobriety checkpoint program. DTNH22-94-C-05064. Washington DC: NHTSA,1999.
Lacey JH, Jones RK & Stewart JR. Cost-benefit analysis of administrative license suspensions. DOT HS 807-689. Washington, DC: NHTSA, 1991.
Langley JD, Wagenaar AC & Begg DJ. An evaluation of the New Zealand graduated driver licensing system, Accident Analysis and Prevention, 28:139-146, 1996.
Levy DT & Miller TR. A cost-benefit analysis of enforcement efforts to reduce serving intoxicated patrons, Journal of Studies on Alcohol, 56(2):240-247, 1995.
McKnight AJ, Tippetts AS & Marques PR. Provisional driver licenses system for follow-up evaluation of Maryland youth license control demonstration project. DOT HS 807 669. Washington, DC: NHTSA, 1990.
Miller TR. The plausible range for the value of life: red herrings among the mackerel, Journal of Forensic Economics, 3(3):17-40, 1990.
Miller TR. The effectiveness review trials of Hercules and some economic estimates for the stables, American Journal of Preventive Medicine, 21: 9-12, 2001.
Miller TR & Galbraith MS. Traffic safety and health care: State and national estimates of employer costs. Network of Employers for Traffic Safety, Washington, DC. 1995.
Miller TR, Galbraith MS & Lawrence B. Costs and benefits of a community sobriety checkpoint program, Journal of Studies on Alcohol, 59(4):462-468, 1998.
Miller TR, Lestina D & Spicer RS. Highway crash costs in the United States by driver age, blood alcohol level, victim age, and restraint use, Accident Analysis and Prevention, 30(2):137-150, 1998.
Miller TR & Levy DT. Cost-outcome analysis in injury prevention and control: 84 estimates for the United States, Medical Care, 38:6, 562-582, 2000.
Miller TR & Levy DT. Reducing highway crash costs: the cost-outcome analyses. In H. von Holst, A. Nygren, & A. Andersson (Eds.). Transportation, traffic safety, and health: Man and machine, Brussels, Belgium: Karolinska Institute, 171–198, 1998.
Miller TR, Spicer RS & Levy DT. How intoxicated are drivers in the United States? Estimating the extent, risks, and costs per kilometer of driving by blood alcohol level. Accident Analysis and Prevention, 31, 515–523, 1999.
National Highway Traffic Safety Administration. Fourth report to Congress: effectiveness of occupant protection systems and their use. DOT HS 808 919. Washington, DC: U.S. Department of Transportation, 1999.
National Highway Traffic Safety Administration. Traffic Safety Facts 2000, DOT HS 809 326. Washington, DC: U.S. Department of Transportation, 2001.
Panko R. Making a Dent In Auto Insurance Fraud, Best’s Review, 65-86, October 2001.
Ross HL. Administrative license revocation in New Mexico: an evaluation, Law and Policy 9(1):5-16, 1987.
Shults RA, Elder RW, Sleet DA, et al., and the Task Force on Community Preventive Services. Reviews of evidence regarding interventions to reduce alcohol-impaired driving. American Journal of Prevention Medicine. 21(4):6-88. 2001.
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Voas RB, Marques, PR, Tippetts AS & Beirness DJ. The Alberta Interlock Program: The evaluation of a province-wide program on DUI recidivism. Addiction, 94(12):1857–1867, 1999.
Voas RB, Tippetts AS & Taylor E. Effectiveness of the Ohio vehicle action and administrative license suspension laws. DOT HS 809-000. Washington, DC: NHTSA, 1999.
Voas RB, Tippetts AS & Taylor E. Temporary vehicle impoundment in Ohio: a replication and confirmation. Accident Analysis And Prevention, 30(5):651-655, 1998.
Voas RB, Tippetts AS & Fell J. The United States limits drinking by youth under age 21: Does this reduce fatal crash involvements? In 43rd Annual Proceedings Association for the Advancement of Automotive Medicine, Des Plaines IL: AAAM, 265-278, 1999.
Voas RB, Tippetts AS & Fell J. The relationship of alcohol safety laws to drinking drivers in fatal crashes. Accident Analysis and Prevention, 32:483-492, 2000.
Williams GD, Stinson FS, Nephew TM, Nguyen K & DuFour MC. Apparent Per Capita Alcohol Consumption: National, State, and Regional Trends, 1977-98, National Institute on Alcohol Abuse and Alcoholism, Surveillance Report No. 55, Rockville, MD: US Department of Health and Human Services, 2000.
Zador PL, Lund AK, Fields M & Weinberg K. Fatal crash involvement and laws against alcohol impaired driving, Arlington, VA: Insurance Institute for Highway Safety, 1988.
Zaloshnja E, Spicer R, Romano E & Miller T. Does using AIS85 costs with AIS90 data create serious errors? In 45th Proceedings of the Association for the Advancement of Automotive Medicine, Des Plaines IL: AAAM, 159-186, 2001.