Proportions for improved stiffness of box section beams used as longitudinal roadside guardrail barriers. Paper presented at the 53rd Annual Meeting of the Highway Research Board HRB, Washington, D.C., January 1974.

Asymmetric box beam cross sections, formed by adding material to the roadside flange, have superior specific stiffness characteristics when compared with symmetric sections designed to meet stability criteria. Stiffness about the major section axis can be increased by as much as 50% while minor axis and torsional stiffness are maintained at levels comparable to a symmetric section. Alternative minor axis and torsional stiffness can both be increased 25% by accepting a marginal 7% increase about the major axis.