Large School Bus Side Impact Stiffness Factors

School bus travel is one of the safest forms of transportation on the road today. The passenger fatality rate in school buses is 0.2 fatalities per million vehicle miles traveled (VMT) as compared to 1.5 per million VMT for passenger cars and 1.3 per million VMT for light trucks. Each year on average, nine school bus passengers are fatally injured in school bus crashes while sixteen school-age pedestrians are fatally injured by the school bus. Although much has been done to improve the safety of school buses over the years, more research may reflect new ways to better protect school bus passengers.

The National Transportation Safety Board concluded in 1999 that current compartmentalization is incomplete in large school buses in that it does not protect passengers during lateral impacts. In order to better understand severe lateral impacts to school buses and the resulting passenger motion and injuries, the stiffness of the side of the school bus needed to be determined.

The purpose of this paper is to present the development of side impact stiffness factors for the large school bus based on previously investigated collisions where a train impacted the side of the school bus.