## 3 Methodology
### Mixed-Method Survey Development  
To thoroughly evaluate the risks identified in the previous analysis, a mixed-method survey was designed with three key components for assessment. The first section gathers respondent information, including their background and familiarity with core concepts relevant to this research, such as BIM, LCSA, and ISO international standards. The second section focuses on the 55 identified risks, each linked to phases of the bridge project lifecycle and evaluated through two distinct lenses. The first lens assesses each risk against the three sustainability pillars (environmental, economic, and social), using a scale of Low, Moderate, and High. The second lens is shown in Figure 2, it uses a risk matrix to figure out the severity and likelihood of each risk's possible effect on the project as a whole, not just one part of it. For this assessment, respondents use a five-point Likert scale to indicate their view on probability (1--Very Unlikely, 2--Unlikely, 3--Possible, 4--Likely, 5--Very Likely) and severity (1--Negligible, 2--Minor, 3--Moderate, 4--Significant, 5--Severe) \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Standard** & **Clause/Section** & **Sustainability Requirements** & **Associated Risks** \\ \hline \multirow{6}{*}{ISO 1404:2006} & \multirow{6}{*}{**4.2**} & Goal and Scope Definition: Define functional unit, system boundaries, and assumptions & - Project Scope Creep - Data Integrity Issues - Poor Communication and Stakeholder Engagement \\ \cline{2-4}  & & Life Cycle Inventory Analysis: Data collection and quantification for accurate lifecycle assessment & - Data Management Challenges - Material Quality and Supply Risks - Resource Planning Issues \\ \cline{2-4}  & & Life Cycle Impact Assessment: Assessment of environmental impacts such as pollution, climate change, water use & - Environmental Compliance Risks - Pollution and Waste Management Issues \\ \cline{2-4}  & & Interpretation of Results: Generate actionable insights for sustainability improvements & - Impact of Climate Change \\ \cline{2-4}  & & Data Quality and Reporting: Ensure data is precise, complete, consistent, and representative & - Data Integrity Issues - Data Management Challenges - Information Management Issues \\ \hline \multirow{6}{*}{**4.2**, **4.3.4**} & Allocation and System Boundaries: Allocation methods and boundary definitions for lifecycle stages & - Project Scope Creep - Inefficient Resource Utilization - Data Use in BIM Processes \\ \cline{2-4}  & & Critical Review and Transparency: Ensure external review and transparent documentation for credibility & - Reputational Risks - Regulatory Compliance Delays - Data Integrity Issues \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Sustainability requirements and associated risks from ISO 14044:2006. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Standard** & **Clause/Section** & **Sustainability Requirements** & **Associated Risks** \\ \hline \multirow{6}{*}{ISO 1404:2006} & \multirow{6}{*}{**4.6**, 7**} & Application of LCA across project phases, including design, construction, maintenance, and decommissioning & - Maintenance Challenges - Budgeting for Future Maintenance - End-of-Life Impacts \\ \cline{2-4}  & & Use of relevant environmental indicators to guide sustainability decisions & - Environmental Monitoring Needs - Pollution and Waste Management Issues - Data Use in BIM Processes \\ \cline{2-4}  & & & \\ \cline{2-4}  & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: _Cont._for each risk. The final section includes an open-ended question, inviting respondents to identify any additional risks not mentioned in the survey and to assess these using the same methods. A total of 75 surveys were distributed to professionals specializing in various types of bridge projects in different countries, such as Syria, the UAE, Saudi Arabia, Hungary, Sweden, Germany, and the Netherlands. Of these, 41 complete surveys were returned and deemed suitable for analysis.