Optimal Staging Area Locations and Material Recycling Strategies for Sustainable Highway Reconstruction

Highway reconstruction consumes large amounts of energy and material resources and at the same time produces significant quantities of emissions during material processing, transportation, and site construction. Sustainable highway reconstruction requires strategies that optimally utilize recycled or virgin material from supply locations (e.g., existing roadway, material markets), assign material use in reconstruction process, select fixed staging area(s) and mobile unit location(s) to process material, and ship the material to the destinations (e.g., markets, landfills, highway construction sites). We present a decision support system based on a network optimization model that determines (i) optimal locations of fixed staging areas and mobile processing units and (ii) optimal material recycling and shipment strategies that minimize the total cost for material procurement, transportation, staging area and mobile processing unit investment, and CO₂ equivalent (CO₂e) emissions. A hypothetical case study of a 35-mile reconstruction project was conducted to test the performance of the model and to draw insights on how different system parameters influence the optimal staging locations, recycled material use, and traffic management plan. It was found that the use of mobile processors and/or recycled material can have significant impacts on hauling costs, emissions, and optimal locations of staging areas.