With increasing traffic being carried by residential streets, combined with the negative effects of climate on pavement material durability and strength and damage due to frequent cutting and patching of the roadway pavement to allow for the placement of utilities, residential streets are requiring more frequent, extensive, and costly maintenance and rehabilitation (M&R). Also, the pavement design life is significantly reduced. The increased cost of M&R and eventual reconstruction is an added burden on already limited city budgets. To rectify this situation, city managers and engineers are analyzing the difference in cost over a 30 year life-cycle for 9- to 10-ton design standard compared to a 5- to 7-ton design standard. Adopting a more significant pavement structure does, however, have significant cost implications, as the initial cost of the pavement is expected to rise significantly. This increase in cost is expected to be offset by a significant decrease in M&R costs and an increase in pavement life that will delay eventual reconstruction. The Minnesota Department of Transportation (MnDOT), on behalf of the Local Road Research Board (LRRB), initiated this study to evaluate the impact of enhancing roadway construction standards to accommodate greater axle loads on local residential streets in Minnesota cities on life-cycle costs. The primary focus of this study was to compare the current residential roadway construction and maintenance life-cycle costs (5- to 7-ton based on construction standards) to the lifecycle costs of residential roadways constructed with 9- to 10-ton standards.
