Incorporating Costs of Life-Cycle Impacts into Transportation Program Development

Ensuring sustainability is necessary for balancing economic viability, the environment, and the social system. Because transportation infrastructure projects have direct and indirect impacts on this balance, transportation agencies must consider the sustainability and environmental impacts of transportation investment during the planning and programming phase. An integrated life-cycle analysis approach (ILCA(2)) that integrates life-cycle assessment and life-cycle cost analysis is developed through the establishment of a reasonable life-cycle time frame, representative elements, largely homogeneous transportation facilities with representative cross sections, and accepted construction, maintenance, and rehabilitation practices. The methodology quantifies life-cycle environmental impacts for the carbon footprint of materials in carbon dioxide equivalent, quantity of wasted materials, and quantity of stormwater runoff along with associated costs. The use of the ILCA(2) is demonstrated for a case study of urban roadway projects in a sample transportation state transportation improvement plan. A case study shows that initial costs represent approximately 20% of life-cycle costs; environmental impact costs are higher than direct operational costs, energy costs, and resurfacing costs. The use of the ILCA(2) for transportation programming allows decision makers to evaluate the larger impacts of transportation investments as well as provides opportunities for considering programmatic changes to practices that support sustainability.