Configurational aftereffects of a stable connection across the Messina Strait: How a bridge transforms the Italian road-circulation network movement patterns.

The idea of a permanent connection and territorial integration between Italy’s mainland in Calabria and the Island of Sicily across the Messina Strait was imprinted on the Italian collective imagination throughout the 20th and 21st centuries. Extensive debates over a bridge construction addressed the political significance, engineering-design feasibility, and building costs for different projects. However, the configurational aftereffects of such traverse remained unaddressed, due to methodological and computational limitations, leaving relevant planning issues out of broader discussions. Considering this, the paper targets to fulfil this gap, by examining how movement patterns are modified by the bridge at local scale, affecting interactions across the Messina Strait, and the possible nationwide configurational aftereffects of this connection. The configurational model for Italy encompasses its highway and primary-road networks, considering Space Syntax’ Normalised measures for Integration and Choice to pinpoint the bridge’s effects on the road network at different scales and radii (Topological Rn and 30km metric radius). Analysis confirms that changes on local-regional urban network hierarchies have divergent effects on the road-circulation network’s relative accessibility distribution across Messina and Reggio di Calabria, while promoting a reorganization of movement patterns at nationwide scales. Findings reiterate the presence of “tunnel effects”, diverting movement potentials and flows elsewhere in the system. This discussion intends to support other spatial analyses that consider how systems’ configuration behave upon inclusion of one or more connective road-elements, demonstrating that effects on network are not always straightforward and that transformations might be perceived only when networks are considered in their entirety.