Regional Difference on Road Recovery in Iwate Prefecture Following the 2011 Tohoku Earthquake

In a previous study, we have calculated the usable road distance in the southern coastal area of Iwate Prefecture following the 2011 Tohoku Earthquake. In this context, a usable road is one on which at least one vehicle has been probed during the observation period. If the accumulative usable distance up to September 30, 2011 is considered as 100%, then the percentage of the usable road distance determined by April 7, 2011 is 80% and 90% by April 29, 2011, respectively. In the current study, we have calculated the regional difference of the road recovery in Iwate Prefecture following the 2011 Tohoku Earthquake. Hence, we have divided Iwate Prefecture into four areas, in particular, the Northern Inland, Southern Inland, Northern Coastal, and Southern Coastal areas, respectively. The main results of our study are as follows. First, we have determined that, for the both Northern and Southern Inland areas, 80% of the road distance has been usable by April 15, 2011 and 90% by May 27, 2011, which indicates that the recovery speed in both the Northern and Southern Inland areas have been slightly slower than that in the Southern Coastal area. Second, we have found that, for the Northern Coastal area, 80% of the road distance has been usable by April 29, 2011 and 90% by June 24, 2011, which implies that the recovery speed in the Northern Coastal area has been extremely slower than that in the Southern Coastal area. Hence, we have concluded that these findings are sustained by the fact that the road recovery efforts have been focused more on the regions heavily affected by the earthquake and consequently by the tsunami.