Estimating the Life-Cycle Cost of Intersection Designs (2016)

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NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Chapter 1–Background Page 1 CHAPTER 1 BACKGROUND This report summarizes the findings of NCHRP Project 03-110, Estimating the Life-Cycle Cost of Intersection Designs. The intended audience for this report consists of federal, state, metropolitan planning organization (MPO), and local engineering and planning staff and consultants; agency planning and engineering managers; and policy makers who make decisions about intersection design alternatives. This introductory chapter presents the problem statement and research objective. 1.1. PROBLEM STATEMENT The following research problem statement comes from the original project request for proposal provided by NCHRP. Roadway infrastructure is costly to build, manage, repair, and replace. Historically, asset investments have been based on expedient design and lowest construction cost. State and local transportation agencies are increasingly considering costs and impacts throughout the life of the project in making investment decisions. Intersections are key components of the roadway infrastructure and the intersection design can significantly impact the maintenance and other costs that accrue after construction. In many cases, costs during the intersection’s life may be shared between different transportation agencies. In addition to direct agency costs, societal costs are significant at intersectionsparticularly crashes, delays, and emissions. There can also be economic impacts on nearby businesses. A life-cycle cost analysis is useful in bringing together factors that can be monetized, but there are often non-monetary agency or community goals that also need to be considered in the design of the intersection. These factors may include a desire to improve the walkability of the network, to preserve the historical or natural context, or to avoid acquisition of a particular property. An agency’s budget, and particularly the available capital, may also constrain the number of feasible designs. Accordingly, the results of a life-cycle cost analysis should inform, but not dictate, the design decisions related to an intersection. There are many methods and data sources for estimating the costs associated with an intersection’s design, and these methods and data sources are continually being updated and improved. A tool is needed to take the available information, determine the life-cycle costs in a consistent and transparent manner, and present the results in a way that facilitates comparison of design alternatives. 1.2. RESEARCH OBJECTIVE As stated in the request for proposals (RFP), the objective of NCHRP Project 03- 110 is “…to develop a spreadsheet-based tool that can be used by an engineer to compare the life-cycle costs of alternative designs for new and existing intersections. The tool will be applicable to the following types of intersections:

NCHRP Project 03-110: Estimating the Life-Cycle Cost of Intersection Designs Final Report Page 2 Chapter 1–Background stop-controlled, traffic signal, roundabout, and innovative designs.” This overall project objective was met by accomplishing the following broad tasks: • Determine a method for conducting life-cycle cost analyses; • Identify the most appropriate performance measures to be included within the analysis; • Identify the most appropriate sources of data that practitioners can use in their life-cycle cost analyses; • Prepare a life-cycle cost estimation tool (the LCCET) that practitioners can use and maintain over the long term; and • Validate the LCCET using a series of test cases with a range of agencies. Ten distinct tasks were identified to achieve the project objective. These include: • Task 1: Methodology • Task 2: Identification of Costs • Task 3: Data Sources • Task 4: Mockup of Interface and Outputs • Task 5: Validation Plan • Task 6: Interim Report and NCHRP Panel Meeting • Task 7: Prepare the Tool • Task 8: Case Studies • Task 9: Final Report • Task 10: Webinar In addition, an initial task to prepare an amplified work plan has been included at the beginning of the project as “Task 0.”