See also: Alcohol
See also: Alcohol Impairment Charts
See also: National .05 BAC
See also: Illinois .08 law: an evaluation
The ABC's of BAC: a guide to
understanding blood alcohol concentration and impairment
This document has been updated and is available as a PDF. Do a Google search on the ABS's of BACs
"Alcohol and Transportation Safety", ALCOHOL ALERT (2001), 52.
Research has shown that even low blood alcohol concentration (BAC)1 impairs driving skills and increases crash risk. New information about BAC and impairment has led to policy changes, which have contributed to declines in alcohol-related crashes and fatalities. This Alcohol Alert examines some aspects of alcohol-induced impairment and reviews selected strategies designed to reduce alcohol-related crashes and repeat drinking-and-driving offenses.
"Alcohol metabolism, "ALCOHOL ALERT (1997), 35 PH 371. (Explains how alcohol is metabolized by the body and factors affecting this metabolism such as food, gender, medications, body weight, and so on.) Address: http://pubs.niaaa.nih.gov/publications/aa35.htm
"Facts about alcohol", Television Corporation of Singapore (1995). ("Recommendations: The legal limit for BAC when operating a motor vehicle should be lowered to 0.050/0. It has been demonstrated in this paper that impairment of vision, motor skills, and cognitive functions occurs at BACs well below the current legal limit of 0.08%, the scientific consensus is that levels of physical impairment significant to the driving task begin at 0.05%. In addition, epidemiologic evidence examined in the document shows that risk of accident begins to increase significantly at or about the 0.05% BAC level.")
Gorman, D. M.; Huber J. C. Jr.; Carozza SE; "Evaluation of the Texas 0.08 BAC law", ALCOHOL AND ALCOHOLISM (2006), 41(2): 193-9. "While there is a growing body of evidence that indicates that 0.08 BAC laws can be effective in reducing alcohol-involved traffic accidents and fatalities, the present study shows that this was not the case in Texas. Future research should move beyond the simple question of whether or not 0.08 BAC laws 'work' and instead explore in more detail the conditions, such as publicity and enforcement, under which the law does or does not contribute to a decline in alcohol-involved accidents and fatalities."
Hindmarch, I.; Bhatti, J. Z.; Starmer, G. A.; Mascord, D. J.; Kerr, J. S.; Sherwood, N.: "The Effects of alcohol on the cognitive function of males and females and on skills relating to car driving," HUMAN PSYCHOPHARMACOLOGY (1992), 7: 105-114. (9 males and 9 females, four doses of alcohol at 1 g per kg body weight or a placebo, Breath. Subjects were tested on two batteries of psychological tests related to skills involved in driving. The results showed a linear increase in the disruption of performance with dose for many of the tests, particularly those involving psychomotor function. It was demonstrated that on certain tasks males were affected ore by alcohol and females. In conclusion, moderate doses of alcohol , resulting in BACs of 0.05 to 0.08 g/100 ml, can produce significant deficits in perceptual and motor skills related to driving a vehicle.)
Hingson, R.; Heeren, T., Winter, M.; "Effect of Mane's 0.05% legal blood alcohol level for drivers with DWI convictions: driving while intoxicated," PUBLIC HEALTH REPORTS (1998), 113 (5): 440-7. (Significant decline in drivers with prior DWI convictions after Maine enacted a law lowering the legal blood alcohol (BAL) from 0.10% to 0.05% for people convicted of driving while intoxicated.)
Hingson, R.; Heeren, T.; Winter, M.; "Lowering state legal blood alcohol limits to 0.08%: the effects on fatal motor vehicle crashes," AMERICAN JOURNAL OF PUBLIC HEALTH (1996), 86 (9): 1297-1299. States who have adopted the .08 BAC law experiences 16% and 18% relative post law declines in the proportions of fatal crashes involving fatally injured drivers whose blood alcohol levels were 0.08% or higher and 0.15% or higher.)
"How effective are .08 drunk-driving laws?", CONSUMERS' RESEARCH MAGAZINE, August (1999), 82 (8: 26-29). (Alcohol is a significant factor in fatal motor vehicle crashes. A .08 BAC law can be a important component of a state's overall highway safety program, but a .08 BAC law alone in not a "silver bullet". Highway safety research shows that the best countermeasure against drunk driving is a combination of laws, sustained public education, and vigorous enforcement.)
Krull, K. R., Smith L. T.; Sinha, R.; Parsons, O. A.; "Simple reaction time event-related potentials: effects of alcohol and sleep deprivation," ALCOHOLISM: CLINICAL AND EXPERIMENTAL RESEARCH (1993), 17 (4): 771-777. (54 males, breath alcohol, two groups .05 and .08, and sleep deprivation. Sleep deprivation slowed initial stimulus detection, whereas alcohol slowed later processing and response activation.)
Miller, T. R.; Lestina, D. C.; Spicer, R. S.; "Highway crash costs in the United States by driver age, blood alcohol level, victim age, and restraint use," ACCIDENT ANALYSIS AND PREVENTION (1998), 30 (2): 137-150. (Notable findings are: (1) crash costs of novice drivers are high enough to yield preliminary benefit-cost ratios around 4-8 for a provisional licensing system that restricts driving after midnight and 11 for zero alcohol tolerance for young divers with violators receiving a 6-month suspension; (2) the cost to people other than the intoxicated driver per mile driven at BACs of 0.08-0.099% exceed the value of driver mobility; (3) the safety costs of drunk driving appear to exceed $5.80 per mile, compared with $2.50 per mile driven at BACs of 0.08-0.099%, and $0.11 per mile driven sober; (4) highway crashes cause an estimated 3.2% of U. S. medical spending, including more than 14% of medical spending for ages 15-24; (5) ignoring crash-involved occupants whose restraint use is unknown, the 13% of occupants who police reported were traveling unrestrained accounted for an estimated 42% of the crash costs; and (6) if these unrestrained occupants buckled up, the medical costs of crashes would decline by an estimated 18% [almost $4 billion annually] and comprehensive costs by 24%.)
Pishkin, V.; Lawrence, B. E.; Bourne, L. E.; "Cognitive and elctro-physiologic parameters during ascending and descending limbs of blood alcohol curve," ALCOHOLISM: CLINICAL AND EXPERIMENTAL RESEARCH (1983), 7: 76-81. (40 men aged 21-30, and peak breath alcohol in the range of 0.08-0.10. Major findings were: cognitive performance was impaired by alcohol ingestion; autonomic arousal was significantly greater after alcohol than after placebo; number and amplitude of skin response were greater on the ascending than on the descending limb; the anticipated effects of failure on cognitive performance were ameliorated by alcohol; and differential effects of alcohol on the psychophysiological parameters were demonstrated.)
Impaired Driving research
Recent research on impaired driving arrests
The ABCs of BAC
Survey of DWI Courts
Evaluation of state Ignition Interlock Programs
Roadside Survey of Alcohol and Drug Use
Drug and Alcohol Crash Risk
Fatality Facts: Alcohol
"Progress has been made since the mid 1990s. Despite earlier declines in alcohol-related highway deaths, about a third of all drivers who die in crashes in the U. S. have blood alcohol concentrations of 0.08 percent or higher. More than 7,000 deaths could have been prevented in 2012 if all drivers were below the legal limits.
The key to reducing alcohol-impaired driving is deterrence. People are less likely to drink and drive if they believe they'll get caught. Sustained and well-publicized enforcement is the best way to let potential violators know they won't get away with it.
Effective measures against impaired driving include:
--administrative licenses suspension
--minimum drinking age of 21
THE MERITS OF A .08 BAC PER SE LAW FOR
The National Highway Traffic Safety Administration (NHTSA) recommends that all states and the District of Columbia establish .08 BAC as the illegal limit per se for drivers aged 21 and older for the following reasons:
(1) Virtually all drivers are substantially impaired at .08 BAC. Laboratory and test track research shows that the vast majority of drivers, even experienced drinkers, are impaired at .08 with regard to critical driving tasks. There are significant decrements in performance in areas such as braking, steering, lane changing, judgment and divided attention at .08 BAC. Studies report that performance decrements in some of these tasks are as high as 60%-70% at .08 BAC.
(2) The risk of being involved in a crash increases substantially by .08 BAC. The risk of being in a crash gradually increases at each BAC level, but rises very rapidly after a driver reaches or exceeds .08 BAC compared to drivers with no alcohol in their blood systems. Research by the Insurance Institute for Highway Safety indicates that the relative risk of being killed in a single vehicle crash for drivers at BACs between .05 and .09 is 11 times that of drivers at .00 BAC (no alcohol).
(3) Lowering the per se limit is a proven effective countermeasure which will reduce alcohol-related traffic fatalities. There is evidence from California that significant reductions in alcohol-related fatalities occurred in 1990 (a 12% reduction), the year .08 and an administrative license revocation law went into effect. A study by Boston University compared five states that lowered their illegal limit from .10 to .08 with five states that did not do so. They found a 16% reduction in the proportion of fatal crashes involving fatally injured drivers whose BACs were .08 or higher in the five .08 states. That same study showed an 18% reduction in the proportion of fatal crashes involving fatally injured drivers at very high BACs (.15 or higher) in those .08 states. A 1995 NHTSA study found significant decreases in four states that adopted .08 on nine measures of alcohol-related fatalities. Decreases in alcohol-related fatalities ranged from 4% to 40% in those states analyzed.
(4) .08 is a reasonable level to set the limit. A .08 BAC is not typically reached with a couple of beers after work or a glass or two of wine with dinner. The average 170 pound male would have to consume more than four 12 oz. cans of beer within 1 hour on an empty stomach to reach .08 BAC. The average 137 pound female would need at least three cans of beer in one hour on an empty stomach to reach that level. That female driver would need 4 equivalent drinks over a 2 hour period to get above .08 BAC and the male would need 5 equivalent drinks.
(5) The public supports levels below .10 BAC. NHTSA surveys show that most people would not drive after consuming 2 or 3 drinks in an hour and believe the limit should be no higher than that. Recent polls show that 2 out of every 3 Americans favor lowering the limit to .08 when they are aware of how much alcohol it takes to reach that level.
(6) Most other industrialized nations have set BAC limits at .08 or lower and have had these laws in place for many years. For example, Canada and Great Britain set their limits at .08--as do Austria and Switzerland. All States in Australia now have a .05 limit. France and Germany recently lowered their limit to .05, while Sweden's illegal limit is .02 BAC.
VALIDATION OF THE STANDARDIZED FIELD SOBRIETY TEST BATTERY AT BACS BELOW 0.10 PERCENT: FINAL REPORT (Burns). This study evaluated the accuracy of the Standardized Field Sobriety Test (SFST) Battery to assist officers in making arrest decisions for DWI at blood alcohol concentrations (BACs) below 0.10 percent. PDF file. Search for it on Google.com for the PDF.
Definition of a heavy drinker--5 or more drinks on one occasion with 5 or more occasions per month.
Philips, D., et. al; "The relationship between serious injury and blood alcohol concentration(BAC) in fatal motor vehicle accidents: BAC = 0.01% is associated with significantly more dangerous accidents than BAC = 0.00%," ADDICTION, June 20, 2011. Researchers at the University of California San Diego, studied 1, 495,667 people who were involved in fatal car crashes from 1994 through 2008. The study comes from the Fatality Analysis Reporting System (FARS) which reports on the blood-alcohol content of drivers in increments of 0.01. he FARS report comes from every U. S. county, all days of the the week and all times of the day. David Phillips, a sociologist a the the university, found that blood-alcohol levels far below the legal limit for drunken driving of 0.08 were linked to serious injury and death in auto crashes. Accidents are 36.6 percent more severe even when alcohol was barely detectable in a driver's blood, Phillips wrote in his published study. Even with a BAC of 0.01, there are 4.33 serious injuries for every non-serious injury verses 3.17 for sober drivers, he stated. The details of the FARS data revealed three main reasons that even low alcohol levels in drivers are linked to more serious injuries: impaired drivers are more likely to speed, they are less likely to use a seat belt, and they are more likely to be the driver of the striking vehicle. . .For example the more the driver has to drink, the greater the speed of the vehicle. The researchers recommend that the current legal limit of 0.08 for driving under the influence be lowered even further, pointing out that the legal limit in Germany is 0.05; in Japan, 3.03; and Sweden, 0.02.
Voas, Robert B.; Tippets, A. Scott; Taylor, Eileen P.; "The Illinois .08 law: an evaluation," JOURNAL OF SAFETY RESEARCH (2002), 33: 73-80. "The proportion of all drinking drivers in fatal crashes was compared before versus after implementing the .08 law using time-series analysis to evaluate 12 years of fatal crash data for Illinois and five bordering states (includes Iowa, Wisconsin, Kentucky, Indiana, and Missouri). The results showed that the proportion of drinking drivers in fatal crashes decreased by 14% in Illinois and and increased by 3% in bordering states. The proportion of drinking drivers in fatal crashes in Illinois, though increasing since 1995, was sharply reduced after passage of the .08 law in 1997, saving more than 100 lives in 1998 and 1999 than would have without the .08 law.
Voas, Robert B.; Taylor, Eileen; Baker, Tara Kelley; Tippetts, A. Scott; "Final Report: Effectiveness of the Illinois .08 law", (DOT HS 809186). This study was conducted using 18 months of data after passage of the .08 BAC law. This analysis indicated that the number of drivers in fatal crashes with positive BACs in Illinois decreased by 13.7%. "(t)he results suggest that the law may be reducing the number of alcohol-related crashes, without having a major impact on the operations of the criminal justice system or the drivers licensing system.
Voas, Robert B.; Tippetts, A. Scott; Taylor, Eileen; "Effectiveness of the Illinois .08 law: an update with 1999 FARS data"; USDOT (DOT HS 809 382), December 2001, 7p. Using FARS (Fatality Analysis Reporting System) data during 30 months beginning July 1997, a reduction of 13.65% was found in the predicted percentage of drinking drivers involved in fatal crashes and the law is associated with the reduction of 105 alcohol related deaths.