Haul Road and Detour Maintenance

Summary

Quantifying and minimizing pavement damage due to detours and haul roads that are part of construction projects represents a very challenging problem. Policies were developed to ensure that roads are returned to pre-construction condition, and overweight trucks can sometimes be allowed to travel on roads through a Minnesota Department of Transportation (MnDOT) permit process. However, due to the complexity of the problem, the current permit assessment is based on a flat fee rather than the damage caused to the pavement.

The research team proposed an approach to quantifying damage by using both traditional and newly developed technologies that can more accurately quantify pavement damage. By measuring pavement deflection using falling weight deflectometer (FWD), rolling wheel deflectometer (RWD), or traffic speed deflectometer (TSD), critical information can be collected about the structural capacity of a pavement structure before and after detouring traffic. Ground-penetrating radar can be used to accurately determine layer thickness, and lidar systems can be used to evaluate the surface condition of the pavement before and after detours.

In addition, damage can be theoretically minimized by rerouting traffic to roads that are in better condition. Although detour routes are explicitly marked, drivers' route choices are not controlled. Researchers constructed a model to predict driver route choices during a construction project, especially for heavy trucks. The link flows predicted by the model informed which additional roads ought to be examined for damage. The model was also extended to suggest optimal detour routes to minimize damage.