Climate change is making our cities more vulnerable, increasing the needs for further policy actions to make them more resilient. In particular, the transport network is critical in the first phase of disaster response. This study presents the epirical findings of a large scale, nationwide analysis of the road network vulnerability in 69 Japanese cities. We (1) identify the level of network efficiency using topological elements in its undisturbed normal state; (2) evaluate the level of network robustness under different random and targeted attack scenarios; and (3) analyze the relationship of the identified network efficiency and robustness indicators with city-level characteristics. The main findings include: (1) cities with a higher population and a higher infrastructure investment tend to be more robust under random attacks; (2) larger cities tend to be less robust to targeted attacks, presumably due to their high agglomeration of urban functions; (3) car dependency tends to make cities more vulnerable toward random attacks and less vulnerable toward targeted attacks as it indicates a weaker concentration in urban functions; and (4) a high modal share for trains tends to make cities less vulnerable toward random events as it indicates a high agglomeration of urban functions. These findings will help policymakers to prioritize their budget allocations to improve nationwide disaster resilience.

气候变化使我们的城市更加脆弱，增加了采取进一步政策行动以使其更具弹性的需求。特别是，运输网络在灾难响应的第一阶段至关重要。这项研究提出了对日本69个城市的道路网络脆弱性进行大规模，全国性分析的实证研究结果。我们（1）使用处于不受干扰的正常状态的拓扑元素来确定网络效率的水平；（2）评估不同随机和针对性攻击情形下的网络鲁棒性水平；（3）分析确定的网络效率和健壮性指标与城市水平特征之间的关系。主要研究结果包括：（1）人口增加，基础设施投资增加的城市在随机袭击下往往更坚固；（2）大城市倾向于针对目标攻击的能力较弱，这可能是由于城市功能高度集聚造成的；（3）对汽车的依赖性往往使城市更容易受到随机攻击，而对目标攻击则较不容易，因为这表明城市功能集中度较弱；（4）火车的高模态份额往往会使城市不易受到随机事件的影响，因为这表明城市功能的高度集聚。这些发现将有助于决策者确定预算分配的优先次序，以提高全国范围的灾难恢复能力。（3）对汽车的依赖性往往使城市更容易受到随机攻击，而对目标攻击则较不容易，因为这表明城市功能集中度较弱；（4）火车的高模态份额往往会使城市不易受到随机事件的影响，因为这表明城市功能的高度集聚。这些发现将有助于决策者确定预算分配的优先次序，以提高全国范围的灾难恢复能力。（3）对汽车的依赖性往往使城市更容易受到随机攻击，而对目标攻击则较不容易，因为这表明城市功能集中度较弱；（4）火车的高模态份额往往会使城市不易受到随机事件的影响，因为这表明城市功能的高度集聚。这些发现将有助于决策者确定预算分配的优先次序，以提高全国范围的灾难恢复能力。