Assessing the effects of the design population on seat dimensions

Abstract

Dimensional recommendations for automotive seat design are often based on populations different from the intended user population. Military data are commonly used to provide guidance for seats used by civilians, for example, because detailed military data are more readily obtained. Even when data from an anthropometric study of civilians are available, target dimensions for automotive seats are often selected under the assumption that the design population is the same as the population measured in the anthropometric study. This report examines the consequences of these assumptions by comparing target values for key anthropometric dimensions for the general U.S. population with estimates for specific populations that may be of interest for seat design. The focus of the investigation is on the importance of gender mix, ethnicity, and market country in selecting target dimensions for seat design. Data from CAESAR, NHANES, the U.S. Census, and ISO 7250-2 were used. The report analysis demonstrates that population definition is important in computing distributions of anthropometric dimensions to be used to guide seat design. In the U.S., gender mix has the potential to be more important than ethnicity distributions across regions.