In Thailand, traffic accidents are a public heath crisis. According to Asian Development Bank, road accidents in Thailand in 2003 killed 13,116 persons and injured 1,529,034 persons. The accidents caused about US $ 3 billion in economic losses or 2.1% of Thailand’s annual gross domestic product(1). The accident data are very poor and incomplete. The real causes of acci- dents are still under study. However, Thai officials blamed drunk driving, speeding and reckless driving as the primary culprits. For many years, police reported statistics have grossly underestimated the magnitude of the problem of drowsy driving. Drowsy driving was always listed at the bottom of all causes of accident