Haul Road and Detour Maintenance

Summary

Highway construction projects frequently require detours and haul roads that divert traffic, including heavy trucks, onto local roads not originally designed for such loads. These temporary routes can accelerate pavement deterioration, reduce service life, and impose significant maintenance costs on local agencies. Current compensation practices, such as Minnesota's Gas Tax Method and Equivalent Overlay Method, offer partial solutions but do not fully capture the variability of damage across different pavements and traffic conditions. This study investigates the structural and economic impacts of detours and haul roads on Minnesota's roadway network and develops a framework for improved evaluation and planning. A comprehensive literature review of empirical and engineering-based approaches to estimating pavement damage is first conducted, along with a survey of compensation practices across U.S. states. Field data are next collected from five detour routes and two haul roads using Falling Weight Deflectometer (FWD), and Ground Penetrating Radar (GPR). The results are then used to estimate Remaining Service Life (RSL). Due to significant variability in FWD testing, MnDOT's calibrated pavement performance curves are applied to estimate damage, with a case study demonstrating that a three-month detour could reduce service life by more than two years. Additionally, a multiclass traffic assignment model is implemented to predict vehicle-type-specific flows under closures, and optimization techniques using genetic algorithms are developed to identify detour routes that minimize truck-related pavement damage while maintaining network efficiency. While the findings provide some practical tools and recommendations for more equitable compensation and improved detour planning, more research is needed to validate the results obtained in this study.