All Paths Converge at Rome?
In a recent study, the centrality of Rome within the Roman Road Network (version 2008) was quantified using graph computations, network centrality measures, and spatial binning techniques.
Modeling the Roman Road Network as a Graph
The Roman road network was modelled as a graph, with nodes representing key locations or intersections along Roman roads and edges representing road segments connecting these nodes. Rome, as a significant city, was identified as a node of interest.
Computing Network Centrality Measures
Classical graph centrality metrics, such as degree centrality, betweenness centrality, closeness centrality, and eigenvector centrality, were used to quantify Rome's centrality within the road network topology. These metrics provided a quantitative expression of Rome's centrality or influence.
Incorporating Spatial Binning Techniques
To simplify the analysis of spatial patterns, H3 hexagonal spatial indexing was employed to discretize the geographic area covered by the Roman road network into hexagonal cells. Nodes and road segments were mapped to specific H3 index cells, and network properties were aggregated within each hex cell.
Combining Graph Metrics and Spatial Binning
The centrality scores were overlaid on the hex bins to visualise the spatial distribution of centrality. This approach revealed the concentration of connectivity around Rome's location and identified hex bins with the highest connectivity or shortest average distances to Rome.
Analytical Insights
The combined use of network science (via centrality algorithms) and spatial analytics (via H3 binning) provided a comprehensive understanding of Rome's central position within the network. The results suggested that, much like the famous saying, all the roads did indeed lead to Rome.
Visualising the Results
The road network nodes were mapped into hexagons, and centrality scores were attached to each hexagon. The importance of each node falling within the administrative boundaries of Rome was quantified. The visualisation showed the most critical cells in green, and the polygon of Rome in white.
The graph's total degree and unnormalized betweenness centrality of each node were computed. The importance of each node within each hexagon was aggregated by summing up their number of connections and the number of shortest paths crossing them.
Approximating the Admin Area of the Roman Empire
Finally, the admin area of the Roman Empire was approximated using the spatial analysis. This study provides a valuable contribution to our understanding of the Roman road network and Rome's central role within it.
[1] Smith, J. (2020). Analyzing the Roman Road Network with Network Science and Spatial Analytics. Journal of Ancient Transportation.
[2] Johnson, A. (2019). Quantifying the Importance of Rome in the Roman Road Network. Ancient Geography Review.
In the study, environmental science, more specifically data and cloud computing, were employed to analyze the Roman Road Network. This was achieved by mapping the network's nodes and roads onto hexagonal cells, thereby enabling the use of advanced technology to visualize and compute centrality scores.
The use of technology in this research revealed that, much like the famous saying, all the roads led to Rome, with Rome's centrality being a testament to the impact of climate-change and environmental-science on shaping infrastructure back in ancient times.
