Assessing the Productivity and the Environmental Impacts of Earthwork Machines: A Case Study for GPS-Instrumented Excavator

This study focuses on the comparison between two similar hydraulic excavators: (i) a traditional excavator and (ii) a Global Positioning System (GPS) instrumented excavator. Both the machines were monitored for the work they performed. This included the moving of large masses of earth as well as finishing tasks of profile refinement (with a constrained accuracy of ± 10 cm). The comparison included the efficiency of machines and attained accuracy as well as their environmental impact with regards to emissions into the atmosphere. The environmental impact calculations were conducted by means of the ECORCE application, a numerical tool for Life Cycle Assessment of road developed at the French Institute of Science and Technology for Transport, Development and Networks (Ifsttar). The monitoring highlighted the fact that GPS-instrumented excavator fully conformed to the accuracy requirements for earth moving. The use of the GPS technology resulted in 1/3 and 2/3 reductions of fuel consumption and finishing working time, respectively. This also contributed to lower both the potential environmental impacts (i.e. global warming potential, acidification potential, eutrophication index, photochemical ozone and eco-toxicity potential indicated) and the related costs.