Economic feasibility analysis of roadway capacity expansion with accounting traffic noise barrier cost

Transportation externalities like air pollution, noise and others are acost or a benefit that arises from an economic transaction and that falls on people who do not participate in the transaction (Perkin, 2000). Among those externalities, noise has become such a pervasive factor in our life recently. Conventional economic feasibility analysis, however, does not account the costs of such externalities. The purpose of this paper is to address the issue of the economic feasibility analysis with accounting such externalities, focusing on traffic noise area. Based on TNM model cost along with conventional construction, right-of-way, and maintenance costs, a revised benefit/cost (B/C) analysis will be conducted for a hypothetical city called U-TOWN. By incorporating the noise cost, represented by the noise barrier cost, the revised B/C indicator can be obtained along with range of cost share by the addition of the noise barrier and the range of B/Cs thereof. This paper, more specifically, proposes the framework of how to incorporate noise element into the existing B/C analysis. It also includes the usage of TNM, noise level prediction method, and how to obtain the optimal design of noise barrier within TNM. If successfully conducted, the analysis framework set forth here in this paper can be further explored and the results may shed light on a new and better framework combining transportation and environmental modeling to better address the environmental aspects of transportation.