Impact of Concentration of Urban Activities on Transport; a Comparative Analysis Between Dutch and Japanese Cities
Cees D. van Goeverden, Delft University of Technology, NLNobuaki Inoue, Fukuoka University, JPKayoko Tsutsumi, Fukuoka University, JP
The paper addresses question whether differences in urban concentration affect urban traffic and pollution. The analysis is based on a comparison between Dutch and Japanese cities with differences in employment concentration.
The urban structures of the large cities in Japan differ from those in Europe. The Japanese cities are typical examples of centralized cities where employment is strongly concentrated in the city centre and the residents live mainly outside the centre. In European cities employment and residence are more mixed, both in the centre and outside. The paper addresses the question whether the differences in urban structure affect urban traffic and its environmental impacts (pollution). The analysis is based on a comparison between a number of cities of different size in the Netherlands and Kyushu. Kyushu is the most southern of the large Japanese islands and has about the same size and population as the Netherlands.
In the study three main stages can be distinguished. The first is mapping the urban structures of the selected cities, in particular with respect to the degree of concentration of employment and residence. The second stage is a demand analysis. Based on travel surveys, the travel patterns of the citizens and visitors of the cities are described regarding trip numbers, trip distances, modal use and trip purposes. The third stage is an attempt to link the differences in urban structures to differences in travel patterns. This is principally done by comparing Japanese and Dutch city pairs of about the same size, because they display large differences in urban structures. However, a problem is that large cultural differences between both countries might have additional (unknown) effects on the travel patterns, making it difficult to separate the urban structure effects. Therefore, also cities in the same country are compared mutually. As a result of this stage, the impact of employment concentration on urban traffic and its carbon dioxide emissions can be estimated.
The study results show that there are indeed large differences in concentration between the Dutch and the Japanese cities. The differences are larger when the cities become larger. For instance, in the centre of Fukuoka ?the largest city of Kyushu? the employment density is 3 to 4 times the density in Amsterdam ?the largest city in the Netherlands? while the residential density in the former is about two third of that in the latter. The demand analysis shows that there are also large differences in demand patterns between the Dutch and Japanese cities. Generally, in Japan trip numbers are less, trip lengths are larger, bicycle use is less and use of both moped and car is higher. There are also differences between cities of different size in the same country. In smaller cities car use is higher and use of public transport is smaller. The relation between city size and travel pattern is stronger in Japan than in the Netherlands. Carbon dioxide emissions, estimated in gram per person per day, are smaller in Dutch cities than in Japanese cities, irrespective of the city sizes. Finally, the study gives no definite answer on the question how urban structure and travel patterns are related, though the results suggest that a mixed performance of employment and residence leads to less car use and less traffic pollution.
Association for European Transport