Lo Chi-yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 42-51). / Abstract in English and Chinese; questionnaires in Chinese. / Abstract --- p.i / Acknowledgments --- p.iv / Table of Contents --- p.v / Chapter CHAPTER 1 --- Introduction --- p.1 / Why is empirical research on driver sleepiness important? --- p.2 / Prevalence of driver sleepiness --- p.2 / Driver sleepiness as a risk factor for traffic accidents --- p.3 / Why should taxi driver sleepiness be studied? --- p.6 / Variations in sleepiness and vigilance and driving performance within a shift and comparison between daytime and nighttime drivers --- p.8 / "The impact of circadian typology on sleep, sleepiness, vigilance and driving performance" --- p.11 / Bright light exposure --- p.14 / Overview of the present study --- p.18 / Chapter CHAPTER 2 --- Main study --- p.20 / Recruitment and Characteristics of Participants --- p.20 / Procedure --- p.20 / Instruments --- p.23 / Chapter CHAPTER 3 --- Results --- p.28 / Chapter CHAPTER 4 --- Discussion --- p.36 / References --- p.42 / Figures --- p.52 / Tables --- p.55 / Appendices --- p.62