Road Network Development Evaluation from the Viewpoint of Emergency Transport Service in Disaster Situation

高速公路极大地有利于应急运输服务，这些服务并不是经常需要的，但从社会的角度来看是非常重要的。提出了一种以应急运输服务为核心的高速公路网评价方法。这种方法的独特之处在于。评价高速公路网改善的效果，不是基于某一特定的OD模式，而是基于该模式。该方法被应用于四国高速公路网的发展。由于采用了最大区位覆盖模型，因此未覆盖人口比率是高速公路网发展的直接评价指标。研究发现，高速公路网的发展可以较大程度地降低未覆盖人口比率。这种影响体现在两个方面。其一是更高速度对高速公路的影响。它。扩大覆盖区域的范围。二是设施区位变化对不同路网的影响。一般情况下，普通公路网与高速公路网的未覆盖人口比率的差值随着设施数量的增加而减小。计算实例表明，在设施较少和最大允许换乘时间较长的情况下，两种路网之间的差值较大，在灾害情况下高速公路网的发展通常比正常情况下更有效，因为普通路网在灾害情况下遭受严重破坏，而高速公路网更可靠。

The expressways greatly benefit emergency transport services which are not often needed but are very important from societies' viewpoint. A method to evaluate the expressway network focused on emergency transport service is proposed in this study. This method is unique in the point that. The effect of expressway network improvement, is not evaluated based on a specified OD pattern but on that. produced by an optimal location problem.The method is applyed to the expressway network development in Shikoku. Since Maximal Location Covering model is used, the uncovered population rate is a direct evaluation index of the expressway network development.It. is found that the value of uncovered population rate can be fairly reduced by the expressway network development. The effect is seen in two aspects. One is the effect of higher speed on expressways. It. enlarges the extent of covered areas. The other is the effect of facility location change on the different road network. Generally, the difference of the value of uncovered population rate between the ordinary and the expressway network diminishes as the number of facilities increases. The larger values of the differences between the two networks are seen in the computation examples with fewer facilities and longer maximum allowable transfer time.The expressway network development is generally more effective in the disaster case than in the normal case because the ordinary road network suffers from serious damage in the disaster case while the expressway network is more reliable.