Quantifying road criticality through the impact of disruptions on pavement deterioration and agency maintenance costs

Road pavement deterioration depends on several factors, such as traffic loads and environmental conditions. Extreme natural hazard events, such as earthquakes, floods, and hurricanes, have significantly damaged road infrastructure over the years, further exacerbating road deterioration. While Transportation Asset Management (TAM) traditionally focuses on normal stressors to estimate road deterioration, recent research has incorporated the effects of natural hazards through fragility and exposure assessments. However, the impact of traffic detours caused by natural hazard events on road remaining life and maintenance costs has not been studied to the best knowledge of the authors. This paper, therefore, proposes a methodology to quantify the effect of highway disruptions on the maintenance cost and remaining life of pavements. The methodology is applied to the South Island of New Zealand, assessing the criticality of primary highway networks, using a “full-scan” approach. Results show that local roads are highly vulnerable to traffic detours, with increases in average monthly maintenance costs up to 289% in the most critical disruptions. The proposed approach offers a valuable tool for transportation agencies to assess road network criticality and predict the consequences of traffic detours following disruptions.