TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 424: Engineering Economic Analysis Practices for Highway Investment explores how U.S. transportation agencies have applied engineering economics--benefit–cost analyses and similar procedures--to decisions on highway investments.

Economic analysis is a critical component of a comprehensive project or program evaluation methodology that considers all key quantitative and qualitative impacts of highway investments. It allows highway agencies to identify, quantify, and value the economic benefits and costs of highway projects and programs over a multiyear timeframe. This research was conducted to provide the Indiana Department of Transportation (INDOT) with a uniform economic analysis methodology. The developed economic evaluation model applies the methodology of life-cycle benefit cost analysis to perform economic analysis for proposed highway projects. As a result of this research, an Excel based computer program, the Indiana Highway Economic Evaluation Model (IHEEM), was developed to provide a convenient tool for INDOT personnel to implement the method. The main costs and benefits contained in the model are agency costs and user benefits. Agency costs include initial costs, routine maintenance costs, rehabilitation costs, and remaining value of the facility. User benefits contain travel time savings, vehicle operating cost savings, and crash reduction savings. In addition to the deterministic method for cost and benefit analysis, an alternative probabilistic approach was also developed and incorporated into IHEEM so that the outputs can be expressed as ranges of values with likelihoods of occurrence.

"Policy-makers often call for expanding public spending on infrastructure, which includes a broad range of investments from roads and bridges to digital networks that will expand access to high-speed broadband. Some point to near-term macro-economic benefits and job creation, others focus on long-term effects on productivity and economic growth. This volume explores the links between infrastructure spending and economic outcomes, as well as key economic issues in the funding and management of infrastructure projects. It draws together research studies that describe the short-run stimulus effects of infrastructure spending, develop new estimates of the stock of U.S. infrastructure capital, and explore the incentive aspects of public-private partnerships (PPPs). A salient issue is the treatment of risk in evaluating publicly-funded infrastructure projects and in connection with PPPs. The goal of the volume is to provide a reference for researchers seeking to expand research on infrastructure issues, and for policy-makers tasked with determining the appropriate level of infrastructure spending"--

This primer provides a foundation for understanding the role of economic analysis in highway decision making. It is oriented toward state and local officials who have responsibility for assuring that limited resources get targeted to their best uses and who must publicly account for their decisions. Economic analysis is presented as an integral component of a comprehensive infrastructure management methodology that takes a long-term view of infrastructure performance and cost. The primer encompasses a full range of economic issues, including economic fundamentals, life-cycle cost analysis, benefit-cost analysis, forecasting traffic for benefit calculations, risk analysis and economic impact analysis.