Urban Esthetic Benefits of Undergrounding Utility Lines in Consideration of the Three-Dimensional Landscape

Since the relative weight of form to function has been increasing in urban planning, from the esthetic viewpoint, many cities in the world have been actively pursuing the undergrounding of overhead utility lines. Esthetic factors are urban externalities in the sense that they are not directly traded in markets. Therefore, we need to control them optimally based on their benefits. In this study, we appraise the benefits of undergrounding utility lines in Japan and clarify the dependency of the residents’ willingness to pay (WTP) on the road width and building height. Our results show that the WTP for undergrounding utility lines is lower as the road becomes wider and the buildings along the road become higher. However, when the road is wide, the WTP does not change much regardless of the height of the buildings. In addition, the average value of the benefit–cost ratios of previous undergrounding projects is from approximately 2.27 to 2.65. However, 3–17% of these projects have benefit–cost ratios of less than 1.