Strategic Road Infrastructure Management : Integrating Geotechnical Risk into Decision-Support Frameworks

Sammanfattning

Road infrastructure is Sweden's primary mode of freight and passenger transport. Maintenance decisions, however, continue to rely predominantly on surface-based condition inspections, which cannot detect hidden subsurface vulnerabilities. This study develops and applies a GIS-based decision-support framework for road maintenance prioritisation in the Malmö–Lund Region (MLR), integrating geotechnical risk with traffic importance through a multi-criteria decision analysis (MCDA) approach. Two composite indicators were constructed from open-access data: the geological risk index (GRI), derived from borehole records of the Geological Survey of Sweden (SGU) for soil sensitivity, groundwater depth, and distance to bedrock; and the traffic importance index (TII), derived from the Swedish Transport Administration (Trafikverket) data on heavy-vehicle traffic volume, heavy-vehicle share, and axle-pair ratio. Both indicators were standardised and combined into a priority index (PI) that weights geotechnical risk more heavily than traffic importance. The analysis shows that the two dimensions are statistically independent, confirming that geotechnical vulnerability and traffic loading capture distinct aspects of road risk. The results also reveal a substantial group of segments with high subsurface vulnerability but low traffic intensity—a hidden geotechnical risk that remains invisible to traditional surface- or traffic-only methods. Burlöv, Malmö, and Kävlinge show the highest mean Priority Index values across the region. Grounded in decision support systems (DSS) theory, bounded rationality, MCDA, and infrastructure asset management, the framework demonstrates that meaningful geotechnical risk screening can be performed using publicly available datasets and open-source GIS software, without additional field investigations or specialist data acquisition.