Uniform Infrastructure Fields: Definition and Identification

This paper discusses the challenge of assessing infrastructure condition using detailed spatial distress data. A new understanding of the spatial behavior of infrastructure is presented and a condition assessment method commensurate with the identified behavior is developed. Two deterioration mechanisms are identified. The environmental mechanism defines deterioration as a consequence of causal factors and exhibits both macroscopic and microscopic scales. The interactive mechanism defines deterioration as a result of distress at a location influencing the deterioration of neighboring locations and exhibits a microscopic scale. The authors propose a nonstationary stochastic spatial model that captures both mechanisms. A methodology based on this model and founded on nonparametric cluster analysis and dynamic programming is developed to identify uniformly behaving fields within which condition can be predicted accurately. The methodology is applied to a 15-km long highway facility, the results of which demonstrate the validity of the spatial model and the need for correctly identifying the uniform fields.