Journal of the Eastern Asia Society for Transportation Studies, Vol.8, 2010 Propagation of Improvement Effects of Critical Inter-city Link --- The Japanese Decadal Change of the Available Travel Routes --- Makoto OKUMURA Makoto TSUKAI Professor Associate Professor Center for Northeast Asian Studies Graduate School of Engineering Tohoku University Hiroshima University 41, Kawauchi, Aoba-ku, Sendai 1-4-1, Kagamiyama, Higashi-Hiroshima 980-8576 Japan 739-8527 Japan Fax: +81-22-795-7477 Fax: +81-82-424-7827 E-mail:
[email protected] E-mail:
[email protected] Yusuke KIMURA East Japan Railway Company Operation and Rolling Stock Department 2-2-2, Yoyogi, Shibuya-ku, Tokyo 151-8578 Japan Abstract: Unlike the urban highway network, the inter-city network is composed of heterogeneous links of various speeds, costs and frequencies. Improvement of one airway link can possibly provide a new attractive travel route, such as an air connection route, as well as multi-modal route, including middle distance railway access. The improvement effect of a critical link may be propagated over the nation-wide network, unlimited to the direct neighbor connector of the improved link. How such propagation occurred in Japan between 1995 and 2005 is investigated. K-th shortest path search algorithm is applied to find the available set of routes. Remarkable changes in the Tohoku-Western Japan pairs are detected. This paper further analyzes the effects of the Shinkansen expansion to Hachinohe in 2002 on the service level of the available routes for those OD pairs, proving that there are strong multi-modal propagations on the air links at Sendai airport.