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、铁路和航线在内的高流动性网络。本研究旨在观察最近的变化，在这种网络的基础上的旅行时间和成本的发展，并从交通用户的角度来评估他们。在评价中，我们提出了一个指标计算的旅行时间和成本之间的地区。对1960年、1970年、1980年和1990年的交通网络分别进行了该指数与交通用户时间价值的比较。本研究获得的主要结果如下。(1)利用成本增加与时间减少的比率，我们指出，从1960年到1970年，旅行成本随着所有运输方式的旅行时间缩短而下降。这意味着这种情况对所有用户都有利。然而，就公路运输而言，1980年至1990年运输服务的区域差距扩大。航空旅行服务的改善对用户来说是极为可取的。(2)在基于成本增加与时间减少的比率和用户的时间价值的分析中，我们发现，对于航空旅行，所有用户都更喜欢在所有领域和每个时期改进后的情况。然而，对于1970年至1980年的道路和铁路使用者来说，大多数人都宁愿选择改善前的情况，问题是这些年来交通费上涨，使使用者负担沉重。在1980-1990年的过去十年中，大多数公路和铁路使用者更喜欢城市地区改善后的状况，但在省级地区，没有多少人有这种感觉。这一结果再次表明，各地区存在运输服务差距。

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.