The objective of this research is to develop guidance coupled with one or more prototypical, analytical model(s) to support life-cycle planning and decision-making that applies life-cycle cost analysis as a component of a system-wide transportation asset management program. This guidance and associated analytical model(s) will apply quantitative asset-level, project-level, and network-level inputs to demonstrate methods for calculating life-cycle costs associated with alternative scenarios while taking into account preservation, rehabilitation, replacement, maintenance, and potential risk mitigation actions on a range of highway assets. To the degree possible, costs should reflect condition, risk and uncertainty, mobility, safety, and any other quantifiable aspect of transportation system performance. Although this research is targeted to state DOT highway assets within the overall transportation network, the research should also identify additional research necessary to expand the process to include other modes.
State and federal policies are increasingly requiring state departments of transportation (DOTs) and other transportation agencies to implement a transportation asset management (TAM) approach to manage their existing assets. Defined as a strategic and systematic process of operating, maintaining, upgrading, replacing, and expanding physical assets effectively throughout their life cycle, TAM requires an agency to focus on strategic business and engineering practices to allocate resources cost effectively so that assets are maintained in the best condition possible, for the longest duration, at the least practicable cost.
State DOTs and other agencies need better economic analysis tools for assessing cost effectiveness of various maintenance treatments, thus enabling them to manage transportation assets more efficiently at the network level. One such industry-accepted practice and tool used by transportation agencies is project level life-cycle cost analysis (LCCA). LCCA is an engineering-economic analysis technique that allows comparison of the relative merits of competing project implementation alternatives. By considering all of the costs—agency and user—incurred during the service life of an asset, this analytical practice guides decision-makers in selecting of projects and other action alternatives that are the most cost effective over their service life.
A limitation of the traditional LCCA practice is its focus on individual project-level analysis which is not always compatible with network-level analysis requiring a broader focus on long-term maintenance and operation of a set of existing assets. Life cycle planning (LCP), however, is a relatively new concept aimed at providing tools and techniques that state DOTs and other transportation agencies can use to conduct an economic cost analysis for a network of transportation assets to manage them cost-effectively over their project life, covering the time each asset goes into service after construction to the time it is disposed of or retired. LCP can take advantage of asset management system capabilities, which include network-level condition data, by applying an engineering-economic analysis approach to evaluate and compare the cost-effectiveness of maintenance strategies to preserve assets at a desired performance level.
While LCP is in its infancy compared with LCCA, the American Association of State Highway and Transportation Officials (AASHTO), the Federal Highway Administration (FHWA), state governments, and international agencies have all developed analytical methods that can be used to create more robust LCP methods and tools. For example, NCHRP Report 713: Estimating Life Expectancies of Highway Assets, documents various methods for assessing the deterioration and life expectancy of a variety of highway assets, including signs, traffic signals, street lighting, sidewalks, culverts, pavements, and bridges. These methods, which can be used to assign an economic value to agency actions taken to maintain existing assets as well as quantifying, in economic terms, user and non-user stakeholder concerns, are foundational to developing more robust LCP analysis tools and techniques.
LCP could become an integral part of a system for managing assets at the network level to evaluate the economic aspects of various actions more effectively and to build strategies a transportation agency can take to increase project longevity. This research is needed to develop guidance and analytical models to enable state DOTs and other transportation agencies to implement a life cycle planning process applicable to TAM.