S.R. Pandi-Perumal, J.C. Verster, L. Kayumov, A.D. Lowe, M.G. Santana, M.L.N. Pires, S. Tufik and M.T. Mello (2006). Sleep disorders, sleepiness and traffic safety: a public health Menace. Brazilian Journal of Medical and Bilogical Research, 39: 863-871
Figure 1. Characteristics of the individual and external factors related to sleepiness that may result in reduced driving performance (adapted from Vesentini et al., 59).