Investigation of the use of a Weibull model for the determination of optimal road link intervention strategies

In this paper, a probabilistic model for the determination of optimal intervention strategies (OISs) for a road link composed of multiple objects that are affected by gradual deterioration processes is investigated. The model is composed of a deterioration part and a strategy evaluation part. In the deterioration part, a Weibull hazard function is used to represent the deterioration of the individual objects, where the values of the model parameters are to be estimated using inspection data. A threshold condition state (CS) for each object is defined, at which an intervention must be executed. The results of the deterioration part are used as inputs in the strategy evaluation part, in which OISs for individual objects and for the link as a whole are determined. The determination of the optimal strategies takes into consideration impacts on multiple stakeholders. The model is demonstrated by determining the OISs for a fictive road link composed of one bridge and two road sections. The main strengths of the methodology are that past deterioration is taken into consideration and that it is possible to consider the execution of interventions simultaneously and, therefore, associated reductions in impacts that normally occur when interventions are grouped. The main weakness of the methodology is that the condition of the objects is represented using only two CSs, i.e. fully operational and not fully operational.