## 7 Focus on Bridge Design  
The focused search for MCDA in Bridge Design returned 15 papers, of which, only 3 were in common with the general search. One of the papers was not relevant as it concerned bridges in electronic circuits. In two others, MCDA methods were not central to the paper but were only mentioned in the context of their potential for use in future research, in one case to develop a sustainability criterion [52], and in another in connection with an automated method for preliminary design of bridges, for instance choice of bridge type, form and materials [53].  
One of the papers was a review of MCDA methods in life cycle sustainability in bridge design, [37], with a somewhat broader search criteria than used here. For instance, the broader term \"Bridge\" was used in the search string whereas here the more specific \"Bridge Design\" was used. In addition, the broader discipline \"Engineering\" was used instead of the various Civil Engineering categories used here. Their search produced an initial set of 31 articles for review. They found that, as here, AHP and SAW were the most common techniques overall but that, in recent years, PROMETHEE and TOPSIS were becoming more popular. MAUT was the least common method. Some specific examples of applications of MCDA to bridge design are given below and summarized in Table 6. In Brazil, a direct use of MCDA compared three bridge types (pre-cast concrete, mixed steel and concrete and timber) [54]. Two MCDA methods were used, AHP and VIKOR with five criteria, including two qualitative criteria, relating to aesthetics and the perception of safety. Both MCDA methods selected the mixed steel/concrete bridge as the best and interestingly, the wooden bridge scored lower on both qualitative criteria. A wider range (5) of candidate structural systems (Cast-in-place, Precast I-Girder, Incremental Launching, Balanced Cantilever, Advanced Shoring method) were considered for earthquake resistance bridges in Greece by [55], using the PROMETHEE method and seven criteria (Safety, Durability, Economy, Construction speed, Aesthetics, Serviceability, and Environmental harmony.) Safety was given the highest weight in the analysis, followed by Durability and Economy, while environmental harmonization was given the lowest weight. Uncertainty was taken into account in the analysis of [56] that used a fuzzy number formulation and optimization together with MCDA methods (AHP and VIKOR). However, only three criteria are used, embodied energy, overall safety, and corrosion initiation time.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Search Criteria:** & & & \\
**All the Multi-Criteria Various** & **Number of** & **Number of Publications in** & **\% of Publications in** \\
**Listed in Section 4 Plus Topics** & **Publications Found** & **Common with Broad Survey** & **Common with Broad Survey** \\
**Listed below** & & & \\ \hline Bridge Design & 15 & 3 & 20.0 \\ Earthquake Engineering & 26 & 3 & 11.5 \\ Cladding & 21 & 1 & 5.0 \\ Sewage Treatment & 38 & 1 & 2.6 \\ Foundation design \({}^{*}\) & 0 \({}^{*}\) & & \\ Truss design & 3 & 0 & 0 \\ Water Supply & 535 & 11 & 2.1 \\ Building Energy & 86 & 11 & 12.8 \\ Route selection & 64 & 2 & 3.1 \\ Transport mode & 14 & 1 & 7.1 \\ \hline \hline \end{tabular} \({}^{*}\) One publication returned but it was not relevant to search topic.  
\end{table}
Table 5: Effect of narrowing focus from discipline to topics.