# Performance-Based Ranking of Existing Road Bridges
## 3 Application of the Assessment Procedure on Case Study Bridges
### Conclusions and the Contribution of the Assessment Procedure  
After collecting the existing knowledge on bridge assessment from practical experience, the damage indicators (e.g., cracks, concrete layer delamination, deformation, etc.) are determined in relation to a specific bridge component (e.g., roadway as part of the traffic surface, main girder, and slab as parts of the bridge superstructure and piers and abutments as parts of the bridge substructure, etc.). The damages are assigned with the corresponding maximum importance associated with the functionality of the corresponding bridge component. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**t (Year)** & **5** & **10** & **15** & **20** & **25** & **30** & **35** & **40** & **45** & **50** \\ \hline \multicolumn{10}{c}{Strategy 1} \\
1. & \begin{tabular}{c} Slab damage \\ repair \\ \end{tabular} & \
\begin{tabular}{c} Roadway \\ cracks repair \\ \end{tabular} &
\begin{tabular}{c} Drain \\ cleaning \\ \end{tabular} & \\
\begin{tabular}{c} Roadway \\ cracks repair \\ \end{tabular} \\
3. & \begin{tabular}{c} Embankment \\ repair \\ \end{tabular} & \
\begin{tabular}{c} Piers \\ damages \\ repair \\ \end{tabular} &
\begin{tabular}{c} Roadway \\ cracks repair \\ \end{tabular} \\
3. & \begin{tabular}{c} Embankment \\ repair \\ \end{tabular} & \
\begin{tabular}{c} Embankment \\ repair \\ \end{tabular} &
\begin{tabular}{c} Ramdas \\ repair \\ \end{tabular} \\
3. & \
\begin{tabular}{c} Embankment \\ repair \\ \end{tabular} &
\begin{tabular}{c} Ramdas \\ repair \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Scheduled interventions on the bridge for two different maintenance strategies. Reprinted with permission from ref. [48]. 2019. IABSE. At the component level, damage assessment indicator \(PI_{DACO}\) of each damage for each component is established, and, by employing weighting of particular damage for relevant component, it is raised to the level of the whole component condition assessment indicator \(PI_{CA,CO}\). Further on, at the level of each component, component indicators of (a) structural safety \(PI_{SS,CO}\), (b) traffic safety \(PI_{TS,CO}\), and (c) durability \(PI_{D,CO}\) are calculated. Then, a transition is made from the component to the system level by adequately weighting each indicator at the component level. The weighting of the four bridge condition assessment criteria \(PI_{DCA,CO}\), based on practical experience in bridge management, is considered as follows: general condition assessment 30%, structural safety 30%, durability 10%, and traffic safety 30%. Furthermore, the key performance indicators of the whole bridge as a system should be revealed as the maximum values among the component indicators: structural safety indicator \(KPI_{SS,SY}\), traffic safety indicator \(KPI_{TS,SY}\), durability issues indicator \(KPI_{D,SY}\), and the general bridge condition indicator \(KPI_{BCA,SY}\). An additional key performance indicator is the bridge availability indicator \(KPI_{AVSY}\), which considers the traffic restrictions that are necessary with respect to the assessed bridge performance. This method also takes into account the importance of the bridge in the network which indicates bridge value \(KPI_{B,NET}\) and is based on five criteria: road category (weight 25%), annual average daily traffic (25%), detour distance (25%), longest span (12.5%), and total length (12.5%). Based on the assessment by visual inspection and weighting at the component, system, and network levels, a set of the six most important key performance indicators is disclosed. It is recommended that the results are presented graphically in the form of a colored spider diagram, accompanied by a tabular overview of the performance indicators. Such a representation can be used in a very descriptive and efficient way for prioritizing the repair of each bridge, but more importantly within the whole network.