“…Given the significant effect of exposure to hazardous environments on the health of taxi drivers, some researchers have emphasized their importance on the occupationally related risk factors contributing to the occurrence of crashes, including fatigue (Christoforou et al, 2012), sleepiness (Firestone, Mihaere, Gander, 2009), vision damage (Maag et al, 1997), mental stress (Mann et al, 2010), duration of working hours 1 School of Highway, Chang'an University, Xi'an, China 2 CCCC First Highway Consultants Co. LTD, Xi'an, China * Corresponding author, e-mail: hityangdong@163.com 43(4), pp. 189-198, 2015 DOI: 10.3311/PPtr.7742 Creative Commons Attribution b research article P P Periodica Polytechnica Transportation Engineering (Hitosugi, 2012), etc.…”