Design attributes of the infrastructure asset were considered as the influencing factors in modeling deterioration in the literature. Madanat et al. (1995) used bridge characteristics affecting the deterioration of bridges such as structural type, span length, wearing surface type, and skew. Micevski et al. (2002) considered pipe characteristics such as diameter, construction material, soil type, and severity of the defects in applying the Markov model for stormwater pipe deterioration as the factors influencing the deterioration process. Subsequent work on the Markov model developed from this study carried out by Tran et al. (2008) also considered the pipe parameters such as size, age, buried depth, pipe slope, and location as the factors influencing deterioration. Micevski at al. (2002) considered exposure conditions of pipes in addition to the traditional pipe characteristics.