# Performance-Based Ranking of Existing Road Bridges
###### Abstract
Visual inspection as a bridge assessment tool is the first stage of the bridge assessment process and provides fundamental information about the bridge condition and defines the need for further assessment [33]. A number of authors use visual inspection data as input to bridge management systems, e.g., [PERSON] et al. [34], [PERSON] and [PERSON] [35], while [PERSON] and [PERSON] use visual inspection data for bridge reliability updating [36]. The comparison of basic visual inspection and more sophisticated Structural Health Monitoring (SHM) as bridge assessment methods is performed by [PERSON] et al. [37]. In Croatia, visual inspection of several bridges of a road network is used as a basis for evaluation of existing assessment methods and the results are presented in the following study [38]. In all countries studied, there is a performance indicator related to this topic. In many countries, this is the only performance indicator used in practice by bridge owners and operators [32]. However, some countries, such as Denmark [39] and the Netherlands [40], have started to use other relevant indicators related to the concepts of remaining service life, safety index or reliability, vulnerability, robustness, availability, and maintainability. The reliability index is of particular interest, but still mainly at the research level. For example, according to [PERSON] et al. [41], [PERSON] et al. [42], and [PERSON] et al. [43], target reliability levels are set based on experience with the performance of existing structures, the consequences of component failures, and construction costs. Having presented in the previous text the diversity of bridge assessment and management procedures around the world, the research presented in this paper aimed to establish the relationship between (a) the current condition assessment procedures in Croatian bridge maintenance practice based on visual inspection and (b) the systematization of key performance indicators (_KPIs_) theoretically established in COST Action TU 1406 to (c) a unique road bridge performance assessment procedure for priority repair ranking. The methodology is as follows. Existing documentation and guidelines applicable in Croatian practice are reviewed. Furthermore, the available scientific and professional documentation within the COST Action TU 1406 is surveyed and analyzed in order to discover the possibilities for further improvement of the existing practical methods. Based on the available data, the analysis method for bridge assessment within the Excel software interface is developed leading to a graphical and tabular presentation of the assessment results. Following an integrated approach, a unique bridge assessment procedure is developed and presented in Section 2. The presented research establishes a relationship between a country-specific bridge condition assessment procedure based on visual inspection and the systematization of key bridge performance indicators developed in the European research, as presented in Section 2.1. The assessment starts at the component damage level (condition of the bridge element), as described in Section 2.2, moves from the component to the system level, as presented in Section 2.3, ascends to the system functionality level (assessment of the whole bridge), as described in Section 2.4, and finally ends at the network priority level (maintenance schedule of all bridges in an infrastructure network), as elaborated in Section 2.5.