A telephone survey was conducted of a random sample of New York State licensed drivers to determine the prevalence and circumstances of drowsy driving. Fifty-five percent of the drivers had driven drowsy within the past year;​ 23 % had ever fallen asleep at the wheel without having a crash, 3 % crashed when they fell asleep, and 2% crashed when driving while drowsy. The fall-asleep/drowsy crashes had the following characteristics:​ driver alone in vehicle (83 %);​ occurring on a highway or expressway (40%);​ occurring 11 p.m.-7 a.m. (60%);​ drive-off-road (48%). Driver variables associated with frequency of driving drowsy in past year included:​ age, education, gender, and work, driving, and sleep/wake patterns.