Regional Highway Construction Cost Index Variation: Structural Disparities, Temporal Drivers, and Mechanistic Insights across the Pandemic Period

Comparing the highway construction cost index (HCCI) across different regions highlights how regional construction costs fluctuate differently over time, revealing regional disparities that statewide averages can mask. These regional differences influence cost projections, budget planning, and resource allocation, underscoring the need for tailored cost management strategies. While prior research has focused on statewide cost indices, limited attention has been given to regional disparities and their underlying drivers, leaving a gap in understanding cost variability and the differences in relative cost fluctuations over time at finer geographic scales. This research investigates regional disparities in HCCI from 2010 to 2023, using a data set that includes Michigan regional cost indices, economic indicators (e.g., unemployment and income), and construction activity metrics (e.g., bidder counts and awarded amounts). The Friedman test confirmed significant heterogeneity across regions (χ2=45.231, p