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

Abstract

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.

Keywords:

• Passenger car
• belt usage
• driver
• injuries
• regression
• Indian crash data

Acknowledgments

The authors gratefully acknowledge the RASSI Consortium, which sponsored the in-depth crash data collection efforts, namely, Robert Bosch GmbH, Nissan Motor Company, Daimler AG, Toyota, Renault SAS, Hyundai KIA Motors, Honda, Autoliv, Maruti Suzuki, TATA Motors, Mahindra Rise, Continental, and JP Research, Inc. The authors also thank the crash investigators at JP Research India for their crash data collection efforts. The RASSI Consortium had no role in the data analysis, decision to publish, or preparation of the article.

Funding

The author(s) reported there is no funding associated with the work featured in this article.