Impact of New Generation Wide-Base Tires on Fuel Consumption

Abstract

This study combined multiple approaches to evaluate the structural and economic impact of using new-generation wide-base tires (NG-WBT) in New Brunswick, Canada. A three-dimensional finite-element model of a typical pavement structure used in New Brunswick was used to predict critical pavement responses. The model includes measured tire-pavement contact forces among other variables overlooked in conventional flexible pavement analysis approaches. Using the model output, regression analysis was performed to predict the responses under various loadings to avoid performing the time-consuming finite-element analysis. Eight-year weight-in-motion data and critical pavement responses were used in transfer functions to predict pavement damage and the corresponding progression of an international roughness index (IRI) during a 60-year analysis period. Most pavement responses from NG-WBT compared with dual-tire assembly (DTA) were 20% and 30% higher in this case. The smallest difference was the vertical strain on top of the subgrade. The life cycle cost analysis (LCCA) considered a reduction in fuel consumption because of the use of NG-WBTs. Two scenarios were analyzed: (1) Case A, in which maintenance was performed periodically and independent of IRI values, and (2) Case B, in which the IRI threshold triggered maintenance. A reduction in fuel costs was significant in both cases. Maintaining a low pavement IRI would increase vehicle and truck fuel cost savings. The results indicate that the agency cost to maintain pavement used by NG-WBT is expected to be between CAD 7,703 to CAD 8,840 (2019 dollars) for 10% and 20% of all tandem axles using NG-WBT per one kilometer for a 60-year analysis period. The annual worth of such savings would be CAD 298 and CAD 342 (2019 dollars), respectively. In contrast, fuel savings per truck-km is expected to be CAD 30,471 to CAD 60,119 (2019 dollars) for 10% and 20% of all tandem axles using NG-WBT per one kilometer for the same analysis period, respectively. The annual worth of such savings would be CAD 1,100 and CAD 2,172 (2019 dollars) per one kilometer, respectively. Additionally, the trucks would save, annually, CAD 0.42 and CAD 0.107 per ton transported per kilometer for 10% and 20% NG-WBT market penetrations, respectively.