# Operational Risk Assessment of Engineering Vehicles Considering Driver Characteristics
## 3 Model Construction
### Classification and Quantification of Risk Indicators  
In China's Overall Emergency Response Plan for Public Emergencies, the warning level is divided into four levels according to the degree of harm, urgency, and development: Level I (particularly serious), Level II (serious), Level III (heavier), and Level IV (safe).  
Figure 5: Schematic diagram of BP neural network structure.  
Engineering vehicle operation's risk assessment is used to assess the degree of danger and the level of risk of engineering vehicle operation as serious, general, basically safe, or safe.  
1. Level I (Serious): The probability of traffic accidents involving engineering vehicles is high, and the consequences are serious. This level of risk is an undesired risk.
2. Level II (General): An engineering vehicle traffic accident may occur with general consequences. This level of risk is conditionally accepted.
3. Level III (Basic Safety): Engineering vehicle traffic accidents are unlikely to occur, and the accident hazard is low. This level of risk is an acceptable risk.
4. Level IV (Safety): The probability of an engineering vehicle traffic accident is minimal, and the accident hazard is slight. This level of risk is the desired risk.  
Through the analysis of data from investigations into accidents involving domestic engineering vehicles, it becomes evident that the occurrence of such accidents often correlates strongly with driver error, as well as adverse road and weather conditions. Moreover, during in-depth investigations into the enterprises involved, varying degrees of management oversight were discovered, serving as factors contributing to the accidents. Hence, this paper proposes three primary risk assessment indicators focusing on drivers, road and environmental conditions, and enterprise management status.  
According to the engineering vehicle operation risk assessment index system, the scoring and assignment method is used to unify the outline of the assessment indicators and facilitate statistical calculations for the qualitative assessment indicators because of the existence of quantitative and qualitative assessment indicators. Moreover, a value between 0 and 10 is taken as the score and to perform the corresponding grade division.  
1. Criteria for Human Factor Risk Assessment
2. Driver's Experience  
Based on statistical analyses of driving experience data from engineering vehicle traffic accidents, it is evident that the likelihood of such accidents is elevated among drivers with limited driving experience. The risk index for driving experience is obtained through the risk assessment index method, with indicators from high to low corresponding to the four levels, namely, serious, general, basically safe and safe, and scored as [0-3], [3-6], [6-8], [6-8], and [8-10] to quantify the assessment indexes, as shown in Table 1.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Level 1 Indicators** & **Secondary Indicators** & **Risk Level** & **Score** \\ \hline \multirow{6}{*}{Driver’s Experience} & Within 2 years & Serious & [0–3] \\  & 3–5 years & General & [3–6] \\  & 5–10 years & Basic Safety & [6–8] \\  & 10–15 years & Safety & [8–10] \\ \cline{2-4}  & \multicolumn{3}{c}{Not wearing a seatbelt} & Serious & [0–3] \\  & Playing with cell phones, receiving and making & & \\ Undesirable Driving Behavior & calls via handheld phones & General & [3–6] \\  & Smoking, controlling on-board equipment & Basic Safety & [6–8] \\  & Others or not present & Safety & [8–10] \\ \cline{2-4}  & 20\% over the permitted speed limit & Serious & [0–3] \\  & More than 10\% and less than 20\% over the & General & [3–6] \\ Traveling Speed & \