The state of Michigan has 191 432 km (118,950 mi) of roadway (paved and unpaved), including highways, roads, and streets. Local government agencies, which are responsible for 176 270 km (109,529 mi) of these roads and streets, commonly use a pavement management system (PMS) called RoadSoft to assist in managing their pavement network. A key element of any PMS is its ability to predict future pavement performance. A study is described in which various deterministic and probabilistic models were evaluated using data from two Michigan counties. It was found that the logistic growth model and the Markov model provided the best combination of predictive ability and potential for applicability in Michigan counties. A comparison between these models found that their predictive ability for four pavement segments with different deterioration rates was good, with the Markov model offering the added advantage of representing future performance as a probability distribution, not as a single condition state. Current plans are to implement the logistic growth model in RoadSoft by the end of 1999 and to add the Markov model as local organizations gather sufficient pavement condition data over the next 5 years. It is hoped that these two pavement deterioration models can be implemented in the RoadSoft PMS to improve pavement performance prediction.

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SUMMARYThis paper investigates the implications of designing for uniform hazard versus uniform risk for lightframe wood residential construction subjected to earthquakes in the United States. Using simple structural models of one-story residences with typical lateral force-resisting systems (shear walls) found in buildings in western, eastern and central regions of the United States as illustrations, the seismic demands are determined using nonlinear dynamic time-history analyses, whereas the collapse capacities are determined using incremental dynamic analyses. The probabilities of collapse, conditioned on the occurrence of the maximum considered earthquakes and design earthquakes stipulated in ASCE Standard 7-05, and the collapse margins of these typical residential structures are compared for typical construction practices in different regions in the United States. The calculated collapse inter-story drifts are compared with the limits stipulated in FEMA 356/ASCE Standard 41-06 and observed in the recent experimental testing. The results of this study provide insights into residential building risk assessment and the relation between building seismic performance implied by the current earthquake-resistant design and construction practices and performance levels in performance-based engineering of light-frame wood construction being considered by the SEI/ASCE committee on reliability-based design of wood structures. Further code developments are necessary to achieve the goal of uniform risk in earthquake-resistant residential construction.