Robust road transportation networks are essential to facilitate truck movements between regions. Disruptions along certain road links could degrade the network’s robustness and curtail regional commerce. A network is considered robust if the network-wide travel cost does not change significantly before and after disruptions. The network robustness index (NRI) is a well-known measure for examining the effect of reduced capacity on one or more links. It has been mainly applied to urban networks and passenger trips. In this paper, the NRI is applied to assess the robustness of the Ontario-wide truck network. Truck flows between the 49 census divisions within Ontario and 25 external zones for the year 2012 are modeled on the network of 35,254 road links and 14,444 associated nodes. Several scenarios of incrementally reduced capacity on specific critical links are devised and simulated. The NRI is calculated for each scenario to identify the level of network robustness. The locational effects of the capacity reductions were explored with the help of maps to assess the change in traffic volumes of the simulated scenarios relative to the base case. As expected, traffic diffuses or shifts to neighboring links when capacities are reduced. These results can be useful in infrastructure planning and the design of alternative routes to minimize the negative impact on traffic flows when disruptions occur.

中文翻译：

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检查安大略卡车公路网的坚固性

强大的公路运输网络对于促进区域之间的卡车运输至关重要。沿某些道路链接的中断可能会降低网络的健壮性并减少区域贸易。如果在中断前后网络范围内的差旅费用没有明显变化，则认为网络很健壮。网络健壮性指数（NRI）是一种用于检查容量减少对一个或多个链路的影响的众所周知的度量。它已主要应用于城市网络和旅客旅行。在本文中，NRI被用于评估整个安大略省卡车网络的鲁棒性。安大略省内49个人口普查部门与25个外部区域之间的卡车流量（2012年）以35,254条道路网和14,444个相关节点的网络为模型。设计并模拟了几种在特定关键链路上逐渐减少容量的方案。为每种情况计算NRI，以识别网络健壮性级别。借助地图探索了容量减少的位置影响，以评估模拟场景相对于基本案例的流量变化。不出所料，当容量减少时，流量会扩散或转移到相邻的链路。这些结果可用于基础设施规划和替代路线的设计，以最大程度地减少发生中断时对流量的负面影响。借助地图探索了容量减少的位置影响，以评估模拟场景相对于基本案例的流量变化。不出所料，当容量减少时，流量会扩散或转移到相邻的链路。这些结果可用于基础设施规划和替代路线的设计，以最大程度地减少发生中断时对流量的负面影响。借助地图探索了容量减少的位置影响，以评估模拟场景相对于基本案例的流量变化。不出所料，当容量减少时，流量会扩散或转移到相邻的链路。这些结果可用于基础设施规划和替代路线的设计，以最大程度地减少发生中断时对流量的负面影响。