MnDOT Haul/Detour Routes – Impacts on local roads

The traffic load on local roadways have changed significantly due to the traffic added from detour and haul routes. Minnesota state law limits the weight of vehicles by individual axles and gross weight. While these laws standardize traditional vehicles by size and weight, when a new pavement is being built, large volumes of heavy vehicles are sometimes diverted through local roads. However, the local road network is often inadequate as these roads are not designed to handle such volume and weight of vehicles. The costs of the resulting premature pavement failure, maintenance, and rehabilitation are the responsibility of local roads authorities who are not generally able to absorb these additional costs. Currently, Minnesota Department of Transportation (MnDOT) determines compensation in these circumstances based on gas tax income generated by the truck highway traffic detoured onto a local roadway. However, there are apprehensions regarding the adequacy of this compensation method to address the damages to the roads. Therefore there is a need to objectively investigate alternative approaches to quantify the reduction in pavement life due to additional traffic in haul/detour routes, and costs associated with this traffic. The primary goal of this study is to analyze alternative “equivalent compensation” methods and develop an agreed-upon approach with stakeholders. This will be achieved through four major tasks: (1) identify, quantify, and evaluate the impacts of changed traffic on the current local roadway systems, (2) forensic investigation on statewide sites, (3) conduct compensation analyses via use of different equivalent compensation methods, (4) develop a web-based tool on the agreed-upon compensation method. The outcomes of this research are anticipated to substantially extend the service life of the local Minnesota road system.