The so-called "driver distraction" occurs when a driver "is delayed in recognition of information needed to safely accomplish the driving task because some events, activities, objects or persons within or outside the vehicle, compelling or tending to include the driver's attention shifting away from the driving task," 1) thus forming a major cause of drivers' inattention. In a word, distracted driving is one of the most significant human factors involved in transport safety. In many countries, the number of motor vehicle crashes has declined over years but distracted-driving induced crashes are increasing significantly in morbidity and mortality [2][3] . Among all kinds of distraction reasons, the mobile phone use is taking an increasingly large percentage 4) . Although nearly all countries and nations have illegalized mobile phone use in driving [5][6] , many people still do so for many functions, such reading or writing text, dialing or conversing in either handheld or hand-free modes, playing games, navigating, etc. According to an investigation by Oren Musicant et al. 7) , phone calls and texting while driving are found to be the most common practice.Mobile phone usage in driving involves a multitude of cognitive and physical resources, which are consistently linked to inferior driving performance [8][9][10][11] . According to a former research 12) , the risk of crashes for drivers who use cell phones while driving is four times higher than others not engaged in such actions, and in a research did later, found the risk of mobile phone use are even under-estimated 13) . According to the research of Schattler et al. 14) , handheld-device conversations resulted in significantly lowered average speed and poor driving performance, while yielding remarkably improper lateral placements and twofold crashes, compared to control conditions. Stavrinos et al. 15) also found very high fluctuation in speed during handheld-device conversation. In addition, Stavrinos et al. 15) and Beede et al. 16) identified a decreased lane-change frequency during conversations on handheld/handsfree mobile phones. Rudin-Brown 17) , Peng 18) , Choudhary 19) and Muttart 20) found that the vehicle control would be worsened when drivers use mobile phones. Distracted driving due to mobile phone uses also affect the braking performances by elongating the brake reaction time, the deceleration adjusting time and the maximum deceleration rate 21) .According to the TPB theory proposed by Ajzen and Fishbein 22) in 1985, attitudes are often labeled as the determinants of studied behavior. Studies 23) shown TPB theory is useful to evaluate the motivations and reason behind the behaviors of texting while driving, and risk perception due to mobile phone. Future efforts in mobile phone prevention would benefit from the development of safe attitudes and enhanced risk literacy. To avoid distracted driving behaviors, it is necessary to conduct research on what factors affect the attitudes.Social capital can be defined as the sum of the resources, actual or v...