Tetsuharu Oba

Research on the causal relationship between urban density, travel behaviours, and transportation energy consumption by economic level

As motorization has progressed around the world, the scope of personal activity is widening due to private-motorized modes (PMM). And due to the increase in PMM, the degree of suburbanization has also increased, resulting in higher energy consumption for transportation as well as global warming. Many studies including that of Newman and Kenworthy have focused on the relationship between urban density and transportation energy consumption. However, the studies were in general focused on a pool of transportation data limited to one country or continent. This geological limitation restrains researchers from gaining insight into different transportation characters as well as a citys economic development status. Therefore, this research was conducted to generate a database of transportation energy consumption by PMM based on person trip data from 119 metropolitan areas in 39 countries. Considering the difference in economic levels of cities around the world, a discriminant analysis was conducted to evaluate the relationship between urban density and transportation characteristics. Based on the results of the analysis, we examined the correlation between urban density and transportation energy consumption by economic level. The analysis showed that the correlation between urban density and transportation energy consumption differs by the citys economic level. Additionally, the more the economic development, the clearer the correlation between urban density and travel behaviours becomes.

Estimating the Efficiency of Transportation Energy Consumption based on Railway Infrastructure and Travel behavior Characteristics

In recent years, energy consumption in the transportation sector by expanding motorization continues to increase in almost every country in the world. Moreover, the growth rate of the transportation energy consumption is significantly higher than those of the civilian and industrial sectors. Therefore, every country strives to reduce its dependence on private transport, which is the main contributor to the transportation energy consumption. In many countries, concepts such as Transit Oriented Development (TOD) or New Urbanism, which controls road traffic by increasing the proportion of the public transportation significantly, have been implemented to encourage a modal shift to public transport. However, the level of change required for eliminating environmental problems is a challenging task. Minimizing transportation energy consumption by controlling the increase of the traffic demand and maintaining the level of urban mobility simultaneously is a pressing dilemma for each city. Grasping the impact of the diversity of the urban transport and infrastructure is very important to improve transportation energy efficiency. However, the potential for reducing urban transportation energy consumption has often been ineffectively demonstrated by the diversity of cities. Therefore, the accuracy of evaluating the current efficiency rate of the urban energy consumption is necessary. Nevertheless, quantitative analyses related to the efficiency of transportation energy consumption are scarce, and the research on the current condition of consumption efficiency based on international quantitative analysis is almost nonexistent. On the basis of this background problem definitions, this research first built a database of the transportation energy consumption of private modes in 119 cities, with an attempt to reflect individual travel behaviors calculated by Person Trip data. Subsequently, Data Envelopment Analysis (DEA) was used as an assessment method to evaluate the efficiency of transportation energy consumption by considering the diversity of the urban traffic features in the world cities. Finally, we clarified the current condition of consumption efficiency by attempting to propose a target values for improving transportation energy consumption.

Measuring walkability and its effect on light rail usage: a comparative study of the USA and Japan

With rising awareness of global warming and its consequences, greater efforts are being made to make our cities more sustainable. Among many factors that can lead to more a sustainable future, policies encouraging walking and the use of public transportation can be considered as major priorities in planning. There is a significant body of research concerning the process of rating the urban structure according to its ease of access for pedestrians and concerning the relationships between walking and public transportation. However, there are few studies focused on the direct relationship between walking and Light Rail Transit (LRT). This study sought to understand the effect of the so-called walkability of urban areas on LRT usage in the USA and Japan. To achieve this goal, an objective, an internationally applicable method for quantifying walkability, was devised using urban structure and street network data in the USA and Japan. Walkability indices derived using this method were used to measure the effect of walkability in station areas on LRT ridership in both countries. Results show that the urban structure around stations in Japanese cities can generally be considered more walkable than cities in the USA. Moreover, station area walkability has a measurable effect on LRT usage, but only in the USA.

How has the Distribution of the Population in Local Cities been Changing over Time According to the Frequency of Railways and Tramways

This paper describes how motorization has become widespread in local cities in Japan. Therefore, city functions and residents have been dispersed to suburbs and daily life has become difficult without private cars. Recently, the concept of a compact city has been attracting attention. It is said that one of the most important keys to realizing a compact city is to develop very convenient public transportation. However, in local cities in Japan, although there are public transportation networks, they are not effectively used because service frequency is very low. This research analyzed the present distributions of populations around stations and how they have changed over time by the levels of service frequencies of railways and tramways in all local cities in Japan. More specifically, at first, the transportation frequencies over railways and tramways and changes in the distribution of population of all local cities in Japan over time were investigated. Then the paper describes how the degree of service frequencies of stations in the public transport system, railways and tramways, and their affect on the present distribution of the population around the stations and their changes over time were analyzed.

Effect of Urban Railroads On the Land Use Structure of Local Cities

This paper on the effect of urban railroads on land use of local cities is from the proceedings of 14th international Conference on Urban Transport and the Environment in the 21st Century, which was held in Malta in 2008. The authors begin with a description of rapid economic growth in Japan that has resulted in rapid motorization, the sprawling of urban functions away from city centers toward the outskirts of cities, and the difficulty of achieving normal activities of every day life without a private vehicle. They then report on their research on 61 cities throughout Japan in which they performed a detailed analysis of the convenience of each city’s public transport (railroad) infrastructure with a particular reference to the population distribution of that city. The results showed that even though some of the cities are formed in such a way to allow citizens to reap maximum benefits from railroad convenience, none of these cities show particularly high levels of public transport utilization. The paper concludes with a discussion of an ideal city designed to maximize the usage and convenience of railroads. The authors identify points of coherence between the ideal city and current Japan cities in the study and describe recent policies intended to revitalize public transport and encourage greater utilization of city railroads.

Structural relationship about pedestrian vibrancy and street environment in central areas of Kyoto, Seoul, Beijing and Florence

In several city centers around the world, there has been a trend to restrain the entry of automobiles and improve pedestrian movement. It is to create central areas that are vibrant with people. However, it is not clear which factors affect vibrancy and how they are related in the city center. We surveyed pedestrians as well as relevant factors on each street in central areas of Kyoto, Seoul, Beijing, and Florence to elucidate the relationship between vibrancy and street environment. Then, structural equation modeling was performed with the survey data to determine the structural relationship between pedestrian vibrancy and street environment. In central areas of these four cities, it is clear that pedestrian comfort has a direct and indirect positive effect on vibrancy, although the existence of parking areas has a negative effect on vibrancy.

The many dimensions of historic preservation value: national and local designation, internal and external policy effects

Abstract This analysis examines the internal and external policy effects of national and local register programmes for historic preservation. Robust hedonic pricing models are crucial to informing policy proposals and understanding how property markets relate to urban heritage. Estimating a repeat-sales hedonic model with neighbourhood trends and spatial mixed models, novel to this literature, offers a marked improvement in terms of jointly identifying internal and external policy effects, comparing national and local designations, separating policy from heritage effects and estimating models robust to spatial dependence and trends in hedonic prices. Historic designation variables, while often individually insignificant in the model, are always jointly significant in explaining varying appreciation rates. Local districts exhibit no consistent price impacts across the models. Being located inside a national district confers a price premium that increases over time in the preferred model specification, while prices fall in national districts’ buffers after designation. The sensitivity of results to model specification raises questions about alternative approaches to spatial dependence in the data in the urban historic preservation context. Evidence of the influence of historic district designation on property turnover and renovation investments is also examined.

Promoting a Policy to Improve the Urban Transportation Environment by a Regional Administrative Organization

We describe the background and results of measures to improve the urban transportation environment by the Hyogo Prefectural Government in the Hanshin-Area, which is part of the Hyogo Prefecture in Japan. Herein we demonstrate the importance of regional administrative organizations to promote improved urban transportation policies and clarify the useful knowledge for other areas considering these types of policies.

Effectiveness of Mobility Management in a Transportation Policy Aimed at Achieving the Kyoto Protocol – Kyoto Project for Studying an Efficient Car Utilization

This paper will discuss that as the first commitment period of the Kyoto Protocol comes to a start, the reduction of greenhouse gas emissions becomes an urgent topic in the transport sector. Although the share of car use in terms of a modal split in Kyoto, where the Kyoto Protocol was born, is rather low compared with other similar scale metropolitan areas around the world, activities concerning all citizens aimed at reducing their car use have become very popular. In particular, Mobility Management, a transportation policy which controls excessive car use by using communication skills, is producing good results. In this paper, the authors will show the successful results of the “Kyoto Project for Studying an Efficient Car Utilization” by introducing two specific projects. One of these is an example of how ridership for railways has dramatically increased as a result of the widespread execution of Workplace Mobility Management, and the other is an example that the ridership of buses has increased because of integration with commuter buses in industrial areas. Based on these results, and paying attention to the execution process of these projects, the authors analyze the factors leading to the successful results. Finally, the authors propose ideas for use in other areas with similar characteristics.