Evaluation of Improvement of High Mobility Networks based on Users'value of Time in Japan

自20世纪60年代以来，机动化的快速发展和航空航线网络的发展改变了日本的运输需求结构。这一变化改善了包括公路、铁路和航空航线在内的高机动性网络。本研究旨在观察基于出行时间和成本的网络发展的近期变化，并从交通用户的角度对其进行评价。在评价中，我们提出了一个由区域间的出行时间和成本计算得出的指标。分别对1960年、1970年、1980年和1990年的交通网络进行了该指数与交通用户时间价值的比较。本研究的主要结果如下：(1)利用成本增加与时间减少的比值，我们指出，从1960年到1970年，所有交通方式的出行成本都随着出行时间的缩短而降低。这意味着这种情况对所有用户都是有益的。然而，在公路运输方面，1980年至1990年运输服务的区域差距扩大了。航空旅行服务的改进对用户来说是非常可取的。(2)基于成本增减比和用户时间价值的分析发现，对于航空出行，在各个领域和各个时期，用户都更喜欢改进后的情况。然而，对于1970年至1980年的公路和铁路用户来说，他们中的大多数人更喜欢改善之前的情况，问题是这几年的交通票价上涨，这给用户带来了经济负担。在1980-1990年的最后十年期间，大多数公路和铁路使用者喜欢城市地区的改进后情况，但在省级地区没有多少人有这种感觉。这一结果再次表明，不同地区的交通服务存在差距。

The rapid progress of motorization and the development of airline flight path networks have altered the structure of the transportation demand in Japan since the 1960's. This change has resulted in improved high mobility networks including roads, railways and airline flight paths. This study aims to observe the recent changes in the development of such networks based on travel time and cost and to evaluate them from the view point of transportation users. In evaluation, we propose an index calculated from travel lime and cost between regions. Comparison of this index to the transportation users' value of time has been evaluated for the networks of 1960, 1970, 1980 and 1990, respectively. The main results obtained in this study are presented below.(1) Using the ratio of cost increase to time reduction, we have pointed out that, from 1960 to 1970, the travel cost decreased as the travel hours became shorter by all modes of transportation. This means that the situation was beneficial to all the users. For road transportation, however, regional gaps in transportation services widened from 1980 to 1990. The improvements in air travel services are extremely preferable to the users.(2) In the analysis based on the ratio of cost increase to time reduction and the users' value of time, we have found that, regarding air travel, all the users preferred the post-improvement situation in all the areas and in every period. For road and rail users from 1970 through 1980, however, most of them preferred the situation before the improvements were made, the problem being the transportation fare hikes during these years, which financially burdened the users. During the last decade, 1980-1990, the majority of road and rail users preferred the post- improvement situation in urban areas, but not very many felt this way in provincial areas. This result again indicates the presence of transportation service gaps by region.