Increasing evacuation flow through school bus emergency roof hatches. (October 2020)

• Record Type: Journal Article
• Authors: Gunter, Leslie; Davis, Jerry; Abulhassan, Yousif; Sesek, Richard; Schall, Mark; Gallagher, Sean
• Is Part Of: Applied ergonomics. Volume 88(2020)
• Publication Date: 2020-10
• Subjects: Accident -- Roll-over -- Evacuation -- School bus -- Surface transportation -- Students -- Emergency exits; Human engineering -- Periodicals; 620.82
• DOI: 10.1016/j.apergo.2020.103178
• Languages: English
• ISSNs: 0003-6870

Abstract

Abstract: Emergency escape roof hatches are used to evacuate school buses in rolled-over orientations. In the United States, the minimum opening size of a roof hatch is defined by Federal Motor Vehicle Safety Standard (FMVSS) no. 217. With the prevalence of rising obesity rates among children, the minimum roof hatch opening size may not be large enough to accommodate larger passengers. Post-accident conditions such as injuries, disorientation, and exit obstructions may also prevent unobstructed passage for egress within acceptable time limits. The purpose of this study was to redesign and fabricate a roof hatch with a larger opening and evaluate its egress characteristics for a range of typical school bus passengers. The larger roof hatch opening allows greater evacuation flow rates, and is almost functionally equivalent to the evacuation flow rate of the front door on an upright school bus. Highlights: Current school bus roof hatch opening size may not accommodate larger passengers. Redesigned roof hatch increases opening area and reduced step-up/down distance. Redesigned roof hatch does not require modification to roof structural components. Evacuation testing of redesigned roof hatch indicates increase egress flow rate. Effective flow rate of redesigned hatch is equivalent to a school bus front door.