Front Airbag Deployment Rates in Real-World Car Accidents in Japan and Implications for Activation of Accident Emergency Calling System

Accident emergency calling systems (AECSs) are signaled by the deployment of airbags, which causes them to automatically emit information providing the location of the accident site to a public service answering party (PSAP). In some real-world accidents, airbags have failed to deploy. This study clarifies the factors that influence the nondeployment of front airbags in vehicle-vehicle collisions, investigating nondeployment of the driver-side front airbags in sedans and light passenger cars (LPCs) from Japanese accident data. The component rates of deployment for front airbags tend to be higher than those of nondeployment at higher values of pseudo-ΔV in vehicle-vehicle frontal impacts. For both sedans and LPCs, the transition zones between nondeployment and deployment of the front airbag occur at pseudo-ΔV values of 30-50 km/h (ΔV ≈ 21-35 km/h). For mutual impact locations where sedans and LPCs impact opponent vehicles at pseudo-ΔV ≥ 40 km/h (ΔV ≈ 28 km/h) in frontal impacts, the component rate of front airbag nondeployment is higher than that of deployment in right-to-right impacts. The results indicate that factors influencing front airbag nondeployment in vehicle-vehicle collisions are ΔV, impact offset configuration, and crossing angle. Considering front airbag nondeployment in real-world accidents, AECSs should have other functions, such as a manual button, to emit information in addition to automatic emission via airbag signaling.