Being sleepy behind the wheel is almost as dangerous as drinking and driving, according to a study from France, with drivers who were either drunk or sleepy at least twice as likely to cause a vehicle accident as their sober or well-rested counterparts.For the study, researchers under the direction of Nicholas Moore at the Center Hospitalo-Universitaire de Bordeaux analyzed information from 679 drivers admitted to a hospital in southwestern France for more than 24 hours because of a serious accident between 2007 and 2009."Sleepiness carried almost as much risk as alcohol ingestion," wrote Moore and his colleagues in a letter in the Archives of Internal Medicine.The researchers used information from driver questionnaires and police reports to determine what may have contributed to the accidents. Drivers reported what medications they were on, their alcohol use and how sleepy they had been before the crash, while patient files provided information on blood alcohol levels.The majority of the injured drivers were under 55 years old and men. Over half were on a motorcycle, about one-third in a car and 10 percent on a bicycle at the time of the accident.