Factors influencing injury severity to belted drivers in car crashes in India.

OBJECTIVE: The 2019 revised Indian seat belt regulation resulted in a significant increase in driver belt use. This study examines the factors influencing Maximum Abbreviated Injury Scale (MAIS) 2+ injuries to belted car drivers using Indian crash data. METHODS: Crash data obtained from Road Accident Sampling System-India (RASSI; 2011 to 2020) were used. Analysis was performed on a sample of 662 belted car drivers, representing 1.7 million drivers nationally. Survey logistic regression was used to identify factors influencing the odds of MAIS 2+ injuries to belted car drivers. Factors including delta-V, mass ratio (striking vehicle/struck vehicle), crash type, and driver age and gender were examined. The model fits and the statistical significance of each factor included in the models were examined. In addition, clinical review of crashes with belted drivers sustaining MAIS 3+ injury is presented. RESULTS: Delta-V was the most significant factor (odds ratio = 12%; 95% confidence interval 6%-19%) influencing belted driver injuries. Older drivers (55+ years) have a higher odds of MAIS 2+ injury. By adding mass ratio to the model, the odds ratio for delta-V increased to 1.16. If the mass ratio is 2.5 (striking vehicle weight = 2.5 times struck vehicle weight), then the odds of MAIS 2+ injury for the struck vehicle driver doubles. The average Delta-V for MAIS 2+ crashes is 34 mph and injury risk increases significantly when delta-V approaches 30 mph. Seventy percent of crashes with injured drivers had a mass ratio >2. For drivers with minor/no injuries, 88% of crashes had a mass ratio <2. Review of MAIS 3+ injury crashes showed that these crashes had a high delta-V (38 mph) and high mass ratio (5). Sixty percent of belted drivers sustained MAIS 3+ head or chest injury resulting from reduction in survival space. About 37% of AIS 3+ head injuries were subdural hemorrhages and 20% were crush injury to head. AIS 3+ chest injuries were rib fractures (40%) and lung lacerations/ruptures (27%). CONCLUSION: Delta-V and mass ratio are significant factors of belted driver injuries in India. Serious injuries are mainly to the head and chest. Increased rear underrun protection device (RUPD) fitment rate, improved airbag and RUPD design, safe speed enforcement, and improved road infrastructure will reduce injury severity.

Characteristics of pedestrian injuries caused due to impacts with powered 2-wheelers in India.

Objective: This study aims to understand the nature, severity, and sources of injuries sustained by pedestrians involved in crashes with powered 2-wheelers (PTWs) in India. Further, it aims to understand the pedestrian injury pattern and injury mechanism based on the pedestrian contact location on the PTW. Methods: Eight years of field data from the Road Accident Sampling System-India (RASSI) database were considered for the study. Analyses were performed using both weighted and unweighted RASSI data. A sample of 57 crashes between pedestrians and PTWs was analyzed to determine the pedestrian injury characteristics, pedestrian orientation with PTW, and PTW contact zone (PCZ) or the pedestrian contact location on PTW. The PCZs were classified into 3 types. The risk of sustaining a Maximum Abbreviated Injury Scale (MAIS) injury to the head and pedestrian injury mechanism across the 3 PCZs was analyzed. Results: The results of both weighted and unweighted RASSI data were consistent. About 67% of pedestrians who were killed sustained MAIS 3+ head injuries and 52% of pedestrians with nonfatal injuries sustained MAIS 2+ lower extremity injuries. The risk of MAIS 3+/fatal head injury is notably higher (86%) for pedestrians struck from behind compared to pedestrians struck from the side (36%). Of the 3 PCZs, about 80% of the pedestrians contacting PCZ-1 (corner of the PTW front end) sustained fatal head injuries and only 5% contacting PCZ-2 (center of the PTW front end) sustained fatal head injuries. About 40% contacting PCZ-3 (combination of PCZ-1 and PCZ-2) sustained fatal head injuries. Of all AIS 3+ head injuries, 88% were associated with ground impacts. Of all AIS 2+ lower extremity injuries, 96% were associated with impacts to PTW front-end parts. Conclusions: The results show that head injuries account for most pedestrian fatalities in crashes with PTWs and lower extremity injuries account for most nonfatal injuries. Head injuries are associated with ground contacts and lower extremity injuries are associated with contacting PTW front-end parts. Pedestrians contacting the corner of the PTW are highly prone to MAIS 3+ head injuries, whereas pedestrians contacting the center of the PTW are less prone to MAIS 3+ head injuries. This difference is predominantly because of the varied injury mechanisms seen across PCZs.