# Digital Twin Framework for Road Infrastructure Management
## 4 Digital Twin Framework for Road Infrastructure Management
### Analysis of Existing DT Frameworks for Road Infrastructure Management
#### 4.1.2 Road Bridges
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Author** & **Application** & **Application/Purpose** & & **DT Layers** & **Layer Type** \\ \hline \multirow{4}{*}{[PERSON] et al. [4]} & \multirow{4}{*}{Bridge maintenance} & & \(\bullet\) & Data and need acquisition layer & \\  & & & \(\bullet\) & Digital modeling layer & \\  & & & \(\bullet\) & Sensor data transmission layer & Applied/ \\  & & & real-time monitoring & \(\bullet\) & Data and model integration layer & Validated \\  & & & & \(\bullet\) & Operation layer & \\ \hline \multirow{4}{*}{[PERSON] et al. [40]} & \multirow{4}{*}{Bridge maintenance} & \multirow{4}{*}{Semantic information visualization using bridge maintenance systems (BMSs)} & \(\bullet\) & Data acquisition layer & \\  & & & \(\bullet\) & Digital 3D modeling layer & \\  & & & \(\bullet\) & Data integration layer & Applied/ \\  & & & & \(\bullet\) & Transmission layer & Validated \\  & & & & \(\bullet\) & Deployment layer & \\  & & & & \(\bullet\) & Service/user layer & \\ \hline \multirow{4}{*}{[PERSON] et al. [41]} & \multirow{4}{*}{Bridge maintenance} & Efficient and safe O\&M; & \(\bullet\) & Data acquisition layer & \\  & & & Agent-based & \(\bullet\) & Communication layer & Applied/ \\  & & & intelligent bridge & \(\bullet\) & Cloud server layer & Validated \\  & & & management & \(\bullet\) & HMI layer & \\ \hline \multirow{4}{*}{[PERSON] et al. [9]} & \multirow{4}{*}{Bridge maintenance} & \multirow{4}{*}{DT-based BMS} & \(\bullet\) & Data acquisition & \\  & & & & (inspection) layer & Generic/ \\  & & & & \(\bullet\) & DT layer & Conceptual \\  & & & & \(\bullet\) & Facility management layer & \\ \hline \multirow{4}{*}{[PERSON] et al. [39]} & \multirow{4}{*}{Bridge management} & \multirow{4}{*}{Enhanced conceptual framework for a bridge DT} & \(\bullet\) & Data collection layer & \\  & & & \(\bullet\) & Data transfer layer & \\  & & & & \(\bullet\) & Data preprocessing and & \\  & & & & & storage layer & Generic/ \\  & & & & \(\bullet\) & DT construction layer & Conceptual \\  & & & & \(\bullet\) & Intelligent decision support & \\  & & & & system layer & \\  & & & & \(\bullet\) & Visualization/control layer & \\ \hline \multirow{4}{*}{[PERSON] et al. [42]} & \multirow{4}{*}{Bridge engineering} & \multirow{4}{*}{DT-enhanced BIM framework for bridge engineering} & \(\bullet\) & Data collection layer & \\  & & & \(\bullet\) & Data preprocessing layer & \\  & & & \(\bullet\) & Data transfer and storage layer & \\  & & & \(\bullet\) & DT model construction layer & \\  & & & & \(\bullet\) & Model updating layer & Generic/ \\  & & & & \(\bullet\) & Data fusion layer & Conceptual \\  & & & & \(\bullet\) & Feedback layer & \\  & & & & \(\bullet\) & Human–computer & \\  & & & & interaction layer & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: DT-layer-based implementations for bridge management applications. to those seen in road infrastructure DTs. It is important to address these inconsistencies when developing a comprehensive and integrated DT framework.