# Mental Health and Safety Assessment Methods of Bus Drivers
## 7 Discussion and Conclusions  
The purpose of this study is to explore the relationship between the demographic characteristics of bus drivers and the severity of unhealthy psychology and negative and impulsive personality on the probability of a driver's traffic accident. By constructing a Bayesian network model of bus driver mental health and traffic safety assessment, the key factors and combination factors of traffic accidents can be quickly and accurately identified. The results of survey experiments and analysis of sample drivers show the following:  
(1) Analysis of demographic factors showed that drivers aged 36-45 were 83.4% less likely to be involved in a traffic accident. This may be because most middle-aged and elderly drivers have rich practical experience in driving, their psychological quality has matured, and their driving adaptability tends to be relatively perfect. There are many situations that do not need to be thought about. With years of driving experience, you can deal with them subconsciously, and creatively overcome various difficulties under conditions that are not conducive to your own driving. Drivers with less than 2 years of driving experience have an approximately 2.4-fold increase in the risk of traffic accidents, which may be due to the lack of driving experience of drivers with low driving experience. They are more sensitive to external stimuli, and most of them are young and high-spirited, and their ability to regulate their emotions is not strong. This is prone to the phenomenon of driving fast and fighting cars, which can easily lead to traffic accidents [16]. (2) The results of the analysis of psychological factors showed that a driver with somatization increased the risk of traffic accident behavior by two times. Drivers with depression and anxiety have a 3-fold and 1-fold increased risk of traffic accident behavior, respectively. This may be due to the relatively fixed driving posture of the bus driver. Moreover, the driver's seat design of most buses in China is not suitable for long-term driving. Due to long hours of work, bus drivers have little time for activities and relaxation, and cannot adjust their bodies well, and are prone to suffer from occupational diseases such as headache, muscle pain, cervical spondylis, stomach disease, and lumbar disc herniation. In addition, drivers with depression and anxiety are more prone to impulsiveness, more  
Figure 8: ROC curve of the accident prediction of the Bayesian network model. iritable, experience a lack of self-confidence and low self-esteem in the process of talking with people, often feel depressed, lose interest in life, are pessimistic, lack energy in usual work, and feel bored with things. If this type of driver encounters congestion on the bus lane and the bus lane is occupied, compared with the non-accident group drivers, they are more likely to become impatient, anxious, and impulsive, and will produce irrational behaviors such as borrowing other lanes to overtake. These illegal or dangerous traffic behaviors are more likely to lead to accidents. (3) The results of the analysis of personality factors showed that the risk of traffic accidents increased by 1.4 and 1.1 times for cyclic tendency and lack of objectivity drivers. Drivers with this type of personality are emotionally changeable, prone to fatigue, and easily excited. Once they encounter overtaking, giving way, and traffic jams, they will feel unhappy and become pessimistic, and are more likely to have traffic accidents. Moreover, such drivers usually take small things to heart, and they are fanciful and cannot judge things calmly and objectively. This character trait is very detrimental to driving safety. (4) The analysis results of the Bayesian network model of bus drivers' mental health and traffic safety assessment showed that the single node states that affect the probability of accidents significantly increase are B2, C1, C3, D2, D3, E1, E2, F1, G3.