Evaluation of Seatbelt and Airbag Effectiveness in Reducing Motor Crash Severe and Fatal Injuries in the UAE
Yaser E. Hawas, Professor and Director of Roadway Transportation and Traffic Safety Research Center (RTTSRC), UAE University, Md. Didarul Alam, RTTSRC, UAE University
Seatbelt and airbag are included in the vehicles to reduce the severity of injury. The study provides the analysis of the effectiveness of seatbelt, and the synthesized effectiveness of seatbelt and airbag comparing the observed injury and fatality.
Seatbelts and airbags are included in most of the vehicles as safety devices to reduce the severity of injury, likelihood of fatality, and costs of motor vehicle crashes. This paper discusses issues related to the effectiveness of these two restraints in the UAE, in case of crashes that result in severe and fatal injuries. This study provides the analysis of the effectiveness of seatbelts, and the synthesized effectiveness of seatbelts and airbags based on comparing the observed injuries and fatalities for occupants protected by the various systems, although the differences in fatality- and injury-reducing effectiveness can be masked by a multitude of factors not directly related to the airbags or seatbelts systems. For this, the detailed crash database is used to conduct the assessment of the effectiveness of seatbelts and airbags. The data was collected from multiple sources including police records, vehicles and site investigation, crash survivor interviews, and hospital records.
Detailed crash data analysis was used to assess the seatbelt effectiveness with the two airbag conditions of deployed or not deployed. The seatbelt usage rate and severity of crashes are presented along with Abbreviated Injury Scale (AIS). The maximum AIS and Injury Severity Score (ISS) for drivers were also estimated for the various combinations of seatbelt use and airbag deployment conditions. Statistical chi-square test and odd ratio were also applied to explore the relation between the variables. The study of the severe and fatal injuries indicated that more than half of the drivers did not use the seatbelt with the airbag deployed, resulting in the increase of the AIS, particularly of head and chest. Furthermore, the use of seatbelt with the deployment of airbags reduces the mean ISS.
The frequencies of severe to fatal head injuries (AIS=4+) are higher in case of seatbelt not used compared to seatbelt used. The frequencies of such severe to fatal injuries are highest in case of seatbelt is not used and airbag is deployed. Additionally, minor chest injuries (AIS=2- ) are more in case of airbag deployment compared to case of airbag non deployment regardless of seatbelt status. More severe chest injuries are encountered in case of no airbag deployment regardless of seatbelt status as well.
The study concluded also that the seatbelt use may generally result in lesser likelihood of head injuries in case of airbag deployment. It may also result in lesser likelihood of chest injuries whether the airbag is deployed or not. It may also result in lesser likelihood of severe head injuries in case of airbag not deployed. Minor to moderate head injuries are likely higher in case of seatbelt use when airbag is not deployed.
This study is limited in the sense it is based on investigating severe and fatal crashes only. It should be clear that such detailed data and crash investigation is quite costly, reaching almost few thousands of dollars for each investigated crash. As such, and due to the limitation of resources it was decided to emphasize only severe and fatal crashes. The significance around many estimates are relatively wide given the limited sample size available in the detailed database. Due to such limitation of data availability, it is not possible to define a model for assessing the association between variables. While the study proves that safety of occupant in motor vehicles can be improved using the seatbelts with airbags, further advances in occupant protection will require more data. Evidence resulting from this research can be used to provide a conceptual basis to the planned introduction and adoption of appropriate public policies, improvements in vehicle and restraint design, and adaptation of occupants’ attitudes and behavior to further increase the protection of occupants.
Association for European Transport