Objective: Though public transport vehicles are rarely involved in mass casualty accidents, when they are, the number of injuries and fatalities is usually high due to the high passenger capacity. Of the few studies that have been conducted on bus safety, the majority focused on vehicle safety features, road environmental factors, as well as driver characteristics. Nevertheless, few studies have attempted to investigate the underlying risk factors related to bus occupants. This article presents an investigation aimed at identifying the risk factors affecting injury severity of bus passengers with different movements.
Method: Three different passenger movement types including standing, seated, and boarding/alighting were analyzed individually using classification and regression tree (CART) method based on publicly available accident database of Great Britain.
Results: According to the results of exploratory analyses, passenger age and vehicle maneuver are associated with passenger injury severity in all 3 types of accidents. Moreover, the variable “skidding and overturning” is associated with injury severity of seated passengers and driver age is correlated with injury severity of standing and boarding/alighting passengers.
Conclusions: The CART method shows its ability to identify and easily explain the complicated patterns affecting passenger injury severity. Several countermeasures to reduce bus passenger injury severity are recommended. 相似文献
Daily PM_(2.5)(particulate matter with an aerodynamic diameter of below 2.5 μm) mass concentrations were measured by gravimetric analysis in Chinese Research Academy of Environmental Sciences(CRAES), in the northern part of the Beijing urban area, from December 2013 to April 2015. Two pairs of Teflon(T1/T2) and Quartz(Q1/Q2) samples were obtained, for a total number of 1352 valid filters. Results showed elevated pollution in Beijing,with an annual mean PM_(2.5)mass concentration of 102 μg/m~3. According to the calculated PM_(2.5)mass concentration, 50% of our sampling days were acceptable(PM_(2.5) 75 μg/m~3), 30% had slight/medium pollution(75–150 μg/m~3), and 7% had severe pollution( 250 μg/m~3). Sampling interruption occurred frequently for the Teflon filter group(75%) in severe pollution periods,resulting in important data being missing. Further analysis showed that high PM_(2.5)combined with high relative humidity(RH) gave rise to the interruptions. The seasonal variation of PM_(2.5)was presented, with higher monthly average mass concentrations in winter(peak value in February, 422 μg/m~3), and lower in summer(7 μg/m~3 in June). From May to August, the typical summer period, least severe pollution events were observed, with high precipitation levels accelerating the process of wet deposition to remove PM_(2.5). The case of February presented the most serious pollution, with monthly averaged PM_(2.5)of 181 μg/m~3 and 32% of days with severe pollution. The abundance of PM_(2.5)in winter could be related to increased coal consumption for heating needs. 相似文献