What is the reaction time of a drunk driver?

Answer 1

Alcohol doesn't directly slow your reactions. Instead, alcohol makes it more likely you'll miss an important cue and not react at all. Or that you'll fall asleep. Research by Herbert Moskowitz in the 1970s showed that alcohol has little effect on reaction time (RT) in simple tasks, but give the person a task that requires divided attention and the odds they'll screw up and miss something goes up and up the more the person drinks. Driving is a divided attention task: you have to divide your attention between lane positioning, speed, position relative to other traffic and making sure that you follow the right route to your destination. When sober, your eyes flick from point to point 4-5 times per second as you gather information about the road and traffic. The more you drink, the fewer times per second your eyes move, so you're collecting less information about what's going on around you and you're more likely to miss something important that could keep you out of a crash. The drunker you get, the more you develop a sort of "tunnel vision" where you only detect cues in the middle of your visual field and miss the cues at the edges of your field of view. Also, the more you drink, the more your eyes stop moving completely for periods longer than 1 second. It's like the lights are on and nobody's home. The famous "Grand Rapids study" in the early 1960s indicated that if your blood alcohol level is up around the legal limit, you're something like 25-50 times as likely to get into a crash.