ABSTRACT
Structural design and evaluation are moving towards reliability based practice. The latest building and bridge design specifications in the US are examples of this trend. In developing these specifications, risks involved with major design factors were modeled as random variables, such as the live load for the structure, the resistance of structural members, the environmental loads due to the wind and flood, etc. The load factors and resistance factors were then derived by controlling the failure of concern. On the other hand, this first generation of reliability based specifications still has ample room for improvement. This paper focuses on one of such issues relevant to maximum load projection for the intended life span of the structure applicable to deriving the truck live load model and its load factor for highway bridge design and evaluation codes.
