Travel time savings vs. logsum-based welfare comparisons under an area-wide road capacity restriction

Abstract

Many studies have been conducted to analyze the impact of road capacity restrictions on transportation networks. Numerous studies related to network capacity restrictions have focused on estimating the inconvenience caused by an increase in travel time as a measurement indicator for capacity restrictions occurring over a short period of time. In terms of network capacity restrictions, this study focuses on monetary loss from the perspective of economic welfare analysis. Using an agent-based model, this study analyzes the effect of disrupting all modes over the short and long term as the capacity of roads is reduced because of area-wide road capacity restrictions. Many studies have used the method of estimating inconvenience caused by increased travel time as an effect analysis, but this study uses logsum-based benefit method; benefit estimated results by the two methods are then compared. A large difference between the two benefit calculation methods was found. In detail, although there was a large loss in terms of increased travel time because of capacity reduction, despite the increase in average travel time because of the long-term change of modes, the derived consumer surplus inconvenience was relatively small because of the adjustment in the utility between modes. The effect of mode conversion was reflected in the benefits of consumer surplus from the perspective of a consumer welfare analysis. The case study showed that the scale of the inconvenience of the consumer surplus method was small because of the highly influential transport policy in small study area, where it was easy to switch between walking and cars. The present study targeted drastic policies that are expected to be quite difficult to accept socially, but a somewhat relaxed scenario analysis is also needed. In addition, it is necessary to consider inconvenient loss for changing the departure time and route in the further studies.