DRIVING IS PERCEIVED AS MORE DIFFICULT FOR LOW BLOOD ALCOHOL CONCENTRATION, BUT PERFORMANCE IS NOT NECESSARILY IMPAIRED

摘要

Alcohol affects perceptual and motor responses. Several researchers have explored the impactof alcohol on driving performance for a BAC (blood alcohol concentration) over 0.065%. In thisstudy, we assessed the effect of BAC on the driving performance at low to moderate alcoholconcentration. Twelve males, (aged: 20-40 years) were tested on four different days with one offour doses of alcohol through beer drinking (1 to 3 bottles, 330 ml at 5% and 1 placebo at0.05%). Dose administration was single-blinded and randomized. Each participant was tested ina fully interactive driving simulator (STISIM Drive 2.0). Participants estimated their level ofintoxication and driving capacity using 100 mm analog visual scales. These scales werecompleted before consumption of alcohol, after consumption-before driving and after driving.After each driving session, subjects also completed a NASA-TLX to estimate their total mentalworkload. Their visual acuity (Snellen chart) was also measured. The average BACs (%) duringthe driving simulation increased with the number of beers taken (placebo: 0 %, 1 beer: 0.019 ±0.005, 2 beers: 0.036 ± 0.006, 3 beers: 0.054 ± 0.009; p<.05). Participants reported anincreased sensation of alcoholic intoxication with the number of beverages drank (on average ona maximum score of 10, 0.08, 1.33, 3.49, and 4.97 for the placebo, 1-, 2-, and 3-beersconditions, respectively; p<.05). They also reported a decreased driving capacity (9.74, 8.83,6.49 and 4.85, for the placebo, 1-, 2-, and 3-beers conditions, respectively; 10 being the highestscore; p<.05). Their visual acuity did not vary with an increasing BAC. As measured with theNASA-TLX, participants reported an increasing mental workload with an increasing BAC (30, 32,41 and 45 for the placebo, 1-, 2-, and 3-beers conditions, respectively; p<.05). The driving,