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Traffic Engineering (TE) is one efficient approach to handle traffic changes. To perform TE, a server called the Path Computation Element (PCE) collects the traffic information from all nodes within the network. Then, the PCE calculates the routes suitable to the current traffic. However, in a large-scale network, it is difficult for one PCE to collect all traffic information in a short period of time. Thus, it takes time to change the routes according to traffic changes. In this paper, we propose a method that changes the routes suitable to the current traffic soon after the traffic changes. In our method, we hierarchically divide the network into multiple ranges; the ranges of the lowest layer are constructed of a small number of nodes and the ranges of the upper layer are constructed from the multiple ranges of the lower layer. We deploy a PCE for each range. The PCEs in the lowest layer change the routes within a small range in a short interval according to the traffic information within the range to handle the traffic changes that occur in a short period of time. Against the traffic change that cannot be handled in the lower layer, the PCEs in the upper layer change the routes within the large ranges of the upper layer according to the aggregated traffic information collected from the PCEs of the lower layer. We also propose a method to aggregate traffic information and a method to calculate the new routes by using the aggregated traffic information considering the upper bounds of link utilizations. In this method, we aggregate traffic information so that we can calculate the upper bounds of the link utilizations after the route change only from the aggregated traffic information. Then, the PCE obtaining the aggregated traffic information calculates the new routes without causing any new congestion by checking the upper bounds of link utilizations calculated from the aggregated traffic information. In this paper, we evaluate our method by simulation and clarif- that our method can mitigate the congestion soon after the traffic changes.