Sleep Deprivation and Alcohol’s role in Motor Vehicle Accidents

Over 110,000 people are involved in motor vehicle accidents; Alcohol and sleep deprivation are the core factors that are the cause of these accidents. A study conducted by AAA Foundation found that 21 percent of all deaths in motor vehicle accidents were due to the lack of sleep. The same study found that getting 4-5 hours is equivalent to driving with a BAC of .08 or higher. The following studies will show the effects of sleep and alcohol intoxication on cognitive performance.

Dr. Gail Baura gave a talk on the study titled THE SLEEP OF LONG-HAUL TRUCK DRIVERS. The paper wanted to see how the lack of sleep and fatigue affects the driving pattern of long-haul drivers. The study was conducted using 20 male truck drivers that were divided into two US and two Canadian groups.  There was a 13-hour late night to morning driving group and a 10 hour a day driving group. All of the drivers were allowed to choose their own bedtime and when they wake up. The researchers used electrophysiological methods to analyze the sleep patterns of the drivers. Also, a psychomotor vigilance task was used to analyze the reaction time to a particular visual stimulus. It was found that the average driver had 5.18 hours of in bed and 4.78 hours of verified sleep; this is less than the average amount of sleep which is 7-9 hours of sleep. The psychomotor performance was reduced if drivers have less than 5 hours of sleep two days in a row. It was also found that accidents are more likely to occur in late night and early morning drivers. This is likely due to the human bodies circadian rhythm, driving in the night naturally makes people drowsier is because of the lack of light.  While this study made some very interesting conclusions it should be important to remember that the same size for this study was small and did not take into account all the different types of truck driving schedules. From this, it would not be reasonable to apply these conclusions to every single truck driver.

Dr. Joanne Fielding is an associate professor of Psychology and Psychiatry at Monash University. Dr. Fielding study: Alcohol and Sleep Restriction Combined Reduces Vigilant Attention, Whereas Sleep Restriction Alone Enhances Distractibility, explores the effect of both alcohol and sleep loss on voluntary and involuntary visual attention processes. The study involved 16 individuals (18-27 years old). The test measured attention by using several different methods including Psychomotor Vigilance Task (PVT) (similar to the previous study), and two ocular tasks, a visually guided one, and antisaccade one. These two tests are used to measure involuntary and voluntary visual movements. The participants were tested under four different conditions, 1: baseline, 2 alcohol (BAC of .05), 3: sleep restricted (only slept 5 hours). And 4: alcohol and sleep restriction combined. The combined condition (sleep restriction/alcohol) showed the slowest reaction time. This condition also showed a decrease in the voluntary allocation and an increase in antisaccade latencies. The sleep condition and the alcohol condition both showed similar increases in antisaccade latencies and reaction time. The results tell us that sleep restriction with alcohol is responsible for decreasing the voluntary visual attention process the most. But individually the sleep restriction and alcohol condition showed similar levels of decrease in the voluntary visual attention process.

            Both studies show that the lack of sleep significantly increases cognitive impairment and also both studies employed similar techniques to monitor their subjects (psychomotor vigilance task). In Dr. Gail Baura study, it is shown that nighttime driving increases drowsiness and a reduced psychomotor performance in drivers with consecutive days of reduced sleep. Dr. Joanne Fielding study showed how sleep restriction and alcohol both have similar effects on cognitive impairments (when alcohol and sleep are combined the cognitive impairments are even worse). People since they first started driving have been told the dangers of drinking and driving, but underestimate how sleep deprivation can have similar effects. These two studies reinforce the dangers of driving impaired, whether that is due to lack of sleep or alcohol. Hopefully, these subjects will get much more mainstream exposure which will help educate the public.

Works Cited

III, Ashley Halsey. “Sleep-Deprived drivers have plenty in common with drunk drivers.” The Washington Post, WP Company, 6 Dec. 2016,

www.washingtonpost.com/local/trafficandcommuting/sleep-deprived-drivers-have-plenty-in-common-with-drunk-drivers/2016/12/06/2f83d166-bbcb-11e6-91ee-1adddfe36cbe_story.html.

Lee, James, et al. “Alcohol and Sleep Restriction Combined Reduces Vigilant Attention, Whereas Sleep Restriction Alone Enhances Distractibility.” Sleep, vol. 38, no. 5, 2015, pp. 765–775., doi:10.5665/sleep.4672.

Mitler MM, Miller JC, Lipsitz JJ, Walsh JK, Wylie CD. THE SLEEP OF LONG-HAUL
TRUCK DRIVERS. The New England journal of medicine. 1997;337(11):755-
761. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2430925/.