Social innovation
Urban planning, Urban policy

How can we restructure the urban structure
by downsizing of activity space in daily life
Division of Global Architecture, Graduate School of Engineering
Assistant Professor Takashi Aoki
https://researchmap.jp/takashi_aoki?lang=en

Abstract
The purpose of this series of studies is to promote the compactness of living areas along major public transportation systems andto examine measures to enable such compactness in reorganizing
mature conurbations. As the first step of this research, we developed indices to measure the compactness of living activity spaceand analyze the actual compactness of them in the Keihanshinconurbation. Daily life activities include various purposes, such ascommuting, purchasing, and leisure activities. Therefore, this paper proposes an index based on the concentration rate of trips by
purpose of daily activities to measure the concentration tendencyof each of these purposes.

Social innovation▍ Background & Results
Sustainable development is attracting attention worldwide, and it
will be essential to compact mature conurbations. However, in a society with a declining population, reduced development pressure,and limited financial resources, it isn’t easy to provide all residential
areas with the same functions to meet the various purposes of daily
activities. Therefore, it is necessary to create urban structures thatallow people to move between multiple areas and use each other’sfacilities according to their purposes, centered on public transportation and other means.
This series of studies focused on “promoting the compactness ofactivity space along major public transportation systems.” As thefirst step, we (1) developed an index to measure the compactnessof lifestyle activity zones and (2) analyzed the concentration of lifestyle activity objectives in each railroad station area.
As an indicator to measure the compactness of living activity
zones, we focused on the number of trips by purpose using personal trip data. We then found a method to categorize the extentof living activity zones by combining the trip concentration rate bypurpose and standard deviation in the railroad station areas. Figure
1 shows a color-coded representation of the typology obtained forthe municipalities in the Keihanshin conurbation. Figure 2 shows
the significant lifestyle combination destinations in the Keihanshin
conurbation. It confirms that more than 30% of railroad stations in
the Keihanshin conurbation have three to four lifestyle destinations
clustered in their station areas.

Figure 1: Types of Municipalities Based on Compactness of Living Activity Areas▍ Significance of the research and Future perspective
The significance of this series of studies is to provide knowledge
contributing to the restructuring of urban structures toward sustainability. Until now, the compactness of activity space has beenmeasured in terms of the total number of trips. However, this biases
the results toward places where the number of trips is concentrated for a specific activity, such as office areas. This paper clarifies
this point by presenting an indicator based on trip concentration
for daily activities for different purposes. In future research, we willkeep analyzing trip concentration by generation and consider areorganization plan for an urban structure that balances the compactness of residential and lifestyle activity areas.
Figure 2: Overlapping types of lifestyle activities in railroad station areas

P a t e n tTr e a t i s e

Aoki, Takashi. Activity space compactness index from the viewpoint of trip arrival point by lifestyle activity purpose in a mature conurbation. Sustainable
Cities and Society. 2023, 88, 104302. doi: 10.1016/j.scs.2022.104302
Aoki, Takashi. Possibility of re-organizing the compact urban structure in the Japanese conurbation from the trip destination prospect. Urban and Regional
Planning Review. 2023, 10, 136-157. doi:10.14398/urpr.10.136

URL
K e y w o r d compact city, urban planning, activity space