Road Usage Recovery in Fukushima Prefecture Following the 2011 Tohoku Earthquake

Cluster Analysis and Discriminant Analysis for Determining Post-Earthquake Road Recovery Patterns

“…Surprisingly, the population density was not significantly correlated with road recovery patterns ( Table 11 ). It shows that the previous study [ 18 ] suggested that the correlation between road recovery and population density was not justified.…”

“…Previous studies [ 17 , 18 ] have not performed outcome testing, which was performed in this study. The results of this study both validated the conclusions of previous studies [ 17 , 18 ] suggesting a correlation between road recovery and topography, while overturning the conclusions of a previous study [ 18 ] correlating road recovery and population density. In addition, a new factor related to road restoration was explored, namely road importance.…”

“…The affected prefectures in the Tohoku region were divided into several large areas, and the authors concluded that road restoration varied between these areas. In two of our previous studies [ 14 , 15 ], the same vehicular driving data from the Toyota Motor Corporation in the Fukushima prefecture were divided into seven regions, and it was found that in the six months following the 2011 Tohoku earthquake, the speed of road use recovery in inland areas was slower than that in coastal areas. We concluded that the recovery of roads was much slower in areas that were narrow, steep-walled, and mountainous.…”

“…We concluded that the recovery of roads was much slower in areas that were narrow, steep-walled, and mountainous. In addition, studies [ 14 , 15 ] compared regions in different prefectures, coastal and inland, that reached 90% recovery rates. These areas had similar recovery dates, which illustrate similar rates of recovery between regions.…”

“…However, this study did not validate the classification results after obtaining the cluster analysis results regarding road restoration. In a related study [ 18 ], we analyzed road recovery in the Fukushima prefecture regarding not only the geographical location and topography but also the population density. In addition, we divided each cluster into four zones and used road closure information to verify the results of the road use recovery.…”