Load and Resistance Factor Design (LRFD) is a design methodology that makes use of load and resistance factors based on the known variability of applied loads and material properties. In 1994, the American Association of State Highway and Transportation Officials (AASHTO) published the first

AASHTO Load and Resistance Factor Bridge Design Specifications

. The Federal Highway Administration (FHWA) mandated the use of LRFD for all bridges for which the Texas Department of Transportation (TxDOT) initiated preliminary engineering after October 2007.