The impact of trucks on road traffic safety has been extensively studied, but the factors influencing truck crash injury severity have not yet been examined from the quarterly perspective. Crash data for Shandong Province in China for 10 years (2012–2021) were reviewed to investigate the transferability of the determinants of the severity of truck crash injuries in four quarters. Three injury severity levels were considered and a random parameters logit model (RPL) considering the heterogeneity of means and variances was constructed to assess the factors affecting the severity of crash injury. The significant variables were explored from the influencing factors of driver, vehicle, crash type, road, environment, and temporal characteristics. A likelihood ratio test was employed to assess the transferability of the crash model over four quarters, and we used marginal effects to analyze the stability of the influencing factors. The results indicated that there was instability among the four quarterly variables that had to be modeled separately. There were also some variables, such as heavy vehicle and multiple-vehicle crashes, that simultaneously affected the severity of truck crash injuries across the four quarters, but the degree of impact was different. The results could enable engineers and policy makers to better formulate management rules and propose appropriate measures according to quarterly changes.

Pedestrian two-stage crossing, as one of the key elements of the urban roadway network, affects not only vehicle flow at signalized interactions, but also road capacities in the transport system. Therefore, it is vital to deeply understand the behavioral characteristics of pedestrian twice-crossing in order to improve the safety and efficiency of the road transport network. Based on our previous study, this study continues to improve the social force model by classifying the trajectory type of pedestrian twice crossing. In the interactive aggregation, the pedestrian trajectory line was divided into two types: straight path and curved path. The Work–Energy Principle and Impulse–Momentum Principle were used to identify the spatial and temporal characteristics of pedestrian twice-crossing behaviors. It was found that when pedestrians on the two sides are facing very close in a congested section, the maximum repulsive force appears to be a dramatic increase and remains for a period of time. This result provides us with direction for updating the social force model, focusing on the repulsive force generated by the opposite flow. The improved model can achieve high precision in predicting pedestrian twice-crossing behaviors. The findings of this study have great implications for designing pedestrian facilities and optimizing pedestrian signal timings, thus helping to increase the mobility and safety of pedestrian twice-crossing.