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Investment Prioritization Methods for Low Volume Roads


Current Transportation Asset Management (TAM) practices use asset condition and utilization metrics such as the Pavement Condition Index (PCI) and Average Annual Daily Traffic (AADT) to prioritize the allocation of funds for preservation, maintenance, repair, and replacement projects. In theory, these metrics permit agency asset managers to direct scarce available funding to those projects that will result in the maximum net improvement to network condition. However, they do not measure the impact of individual projects on the economy because they assume that the alternative that has the highest AADT will translate to the highest positive impact. This assumption has been found to be incorrect in states with a high percentage of low volume roads with a high percentage of trucks that transport not only agricultural and industrial products to market, but serve energy-resource-wise sectors. In these cases, the net impact of network improvement is directly proportional to the value of the commodities being transported to the state’s economy.

A recent study by the Iowa DOT investigated the use of a metric used by the World Bank to prioritize funding for aid in developing countries. The metric is termed the Social Return On Investment (SROI) and takes a holistic view of the economic impact of improvements on low volume roads and bridges. The study used SROI to justify funding the replacement of a bridge that carried 80 AADT over a competing project to replace a bridge that carried 800 AADT because the lower volume bridge serviced a much greater area of corn and soy bean acreage and eliminated a much longer detour for heavy vehicles that could not cross the weight limit posted bridge. Additionally, the use of a return on investment methodology creates the ability to better articulate the outcome of the decision-making process to stakeholders, such as legislators, because it does not require specialized knowledge (i.e. pavement engineering for Pavement Condition Index (PCI)) to understand. SROI is merely one metric that extends the ability of the agency asset manager to intelligently make asset improvement funding decisions. There are many other such metrics available in the literature and potentially in use by State Highway Agencies (SHA).


The objectives are: (1) to identify metrics available to quantify an asset’s economic impact, (2) to identify the tools like databases, software, and other instruments that have been effectively used on past projects, (3) to synthesize current decision parameters for asset management for low volume assets, (4) to identify and document other procedures and processes that integrate innovative metrics into the decision process along with traditional metrics like PCI and AADT, and (5) to identify and document proven procedures for applying these metrics to preservation and maintenance projects.

Sponsoring Committee:AKD30, Low-Volume Roads
Source Info:Standing Committee on Low-Volume Roads, (AFB30). Cosponsors: TRB Standing Committees on Pavement Preservation (AHD18), Bridge Management (AHD35), Chemical, Mechanical and Asphalt Stabilization (AFS90), Transportation Asset Management (ABC40), and Transportation Needs of National Parks and Public Lands (ADA40)
Date Posted:03/15/2019
Date Modified:04/18/2019
Index Terms:Low volume roads, Asset management, Investments, Return on investment, Economic impacts, Highway maintenance,
Cosponsoring Committees:AKT20, Pavement Preservation; AKT50, Bridge and Structures Management; AFS90, Chemical, Mechanical, and Asphalt Stabilization; AJE30, Transportation Asset Management; AEP20, Transportation Needs of National Parks and Public Lands
Planning and Forecasting

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