Life cycle analysis can be primarily in terms of life cycle cost analysis (LCCA) but can also include considerations of resource conservation, environmental impacts, energy balance, etc. In any case, a key question is what constitutes a reasonable time horizon for life cycle analysis. The suggestion is that it should involve short, medium and long term periods, in the order of 25, 50 and 100 years, respectively. Further, using this approach, it is possible to develop a context for LCA of likely and uncertain societal activities, including transportation, over the short, medium and long terms. A numerical example is provided which shows how an agency can determine the internal rate of return (IRR) for two investment alternatives involving different pavement designs and a life cycle period of 50 years. As well, a cost-effectiveness example is provided for a sidewalk network and again a life cycle period of 50 years which shows how the best investment alternative has been identified. For the covering abstract of this conference see ITRD number E211426.
Abstract