Sensitivity of Long-Term Infrastructure Condition to Initial Quality

Infrastructure condition throughout the lifetime of a facility is in part influenced by factors that are decided upon during initial design and construction. This paper presents a framework for exploring the sensitivity of the long-term infrastructure condition to changes in initital quality variables. Such variables, in addition to influencing design and construction costs, are expected to affect deterioration. Deterioration increases maintenance requirements and, consequently, the corresponding cost incurred in operating the system. Hence, there are two dimensions to the problem of interest. On the one hand, the economic perspective is concerned with the relationships among the costs associated with the various provision decisions and activities over the lifetime of a facility. On the other hand, the deterioration perspective is explicitly concerned with the actual initial quality and the physical degradation process. Two approaches aimed at exploring both dimensions are presented, and two corresponding example cases relating to light rail transit infrastructures and highway bridge decks are used for illustrative purposes. The value and limitations of both approaches along with their relationship are also discussed.