EST Case Studies and Perspectives in Japan

  • YuichiE Moriguchi National Institute for Environmental Studies, Traffic Pollution Control Research Team, PM2.5 & DEP research project group
  • Hirokazu Kato Department of Sustainable Transport and Spatial Development, Graduate School of Environmental Studies


Results and discussion of the Environmentally Sustainable Transport (EST) Case Study for Japan are introduced within this paper. According to procedures defined in the EST project by the OECD, the targets for a major reduction of environmental load within the transport sector are defined to be CO2, NOx, PM, and VOC. Three scenarios to accomplish these reduction targets, with respect to these environmental loads are detailed: a technooptimistic scenario (EST1), a transport demand management scenario (EST2), and a composite scenario (EST3). All of the scenarios are examined and compared to the business-as-usual (BAU) scenario. Policy instruments to realize these scenarios and their socioeconomic impacts were, to date, not assessed within the study. Utilizing a “back casting” methodology, expected changes in technology and transport behavior in order to meet an ultimate target of emissions reduction were examined by each of the scenarios. The objective areas consisted of a national study, encompassing the whole of Japan, and a regional (Aichi prefecture) study.

The forecasts indicate that CO2 emissions increase by about 10% in Japan but are almost stable in Aichi prefecture. NOx and HC emissions in 2030 are about half, and PM emissions around one quarter of those in 1990 in Aichi prefecture. The results of the back casting indicate that CO2 and NOx reduction targets have severely restrictive conditions. The achievement of targets utilizing only EST1 and EST2 is totally unfeasible. Even in the combined EST3 scenario, and in light of current trends requirements must include strong recommendations for change such as the significant wide spread use of fuel cell vehicles and the reduction of freight transport demands, and hence the scenario still needs to be discussed further.

How to Cite
MORIGUCHI, YuichiE; KATO, Hirokazu. EST Case Studies and Perspectives in Japan. European Journal of Transport and Infrastructure Research, [S.l.], v. 4, n. 1, mar. 2004. ISSN 1567-7141. Available at: <>. Date accessed: 25 nov. 2020. doi: