Abstract Road systems provide a set of essential services to modern societies, and as such, their functioning becomes crucial to sustaining urban ecosystems. Understanding infrastructure robustness is one with understanding how major disruptions affect the functionality of the overall infrastructure network. Preparing for and responding to unexpected disruptions call for a broad understanding of robustness and a variety of disruption scenarios. The purpose of this study is to analyze how a broad range of disruption magnitudes affects the robustness of the Zurich road network under three factors of influence: network growth in time, disruption strategy, and topological metrics. Our case study was the road system of Zurich in 1955 and 2012, modeled with roads as edges and junctions as nodes. We applied the percolation theory framework to analyze fragmentation processes on the network structure. We introduced two strategies to evaluate the fragmentation processes, the “targeted-randomized” and “attractor-guided” strategies, which use two betweenness centrality (BC) metrics as proxies of the value at risk for each road. The analysis yielded four major findings. First, the Zurich road network demonstrated a phase transition with a loss of approximately 90% of its functionality at a range of 0.1–0.4 of disrupted edges. Second, the distribution function of the robustness index was more robust in 2012 than in 1955. Third, the attractor-guided and targeted-randomized disruption strategies did not yield significant differences in how they affected the network robustness. Fourth, the two BC metrics also yielded a minor influence on the overall robustness. Future studies can extend the temporal analyses to a wider timeframe and combine commuter trips to assign a new value at risk of roads in fragmentation analyses.

中文翻译：

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不同中断过程下苏黎世路网的鲁棒性响应

摘要 道路系统为现代社会提供了一系列基本服务，因此，它们的功能对于维持城市生态系统至关重要。了解基础设施的稳健性就是了解重大中断如何影响整个基础设施网络的功能。为意外中断做准备和响应需要对稳健性和各种中断场景有广泛的了解。本研究的目的是分析范围广泛的中断幅度如何在三个影响因素下影响苏黎世道路网络的稳健性：网络时间增长、中断策略和拓扑指标。我们的案例研究是 1955 年和 2012 年苏黎世的道路系统，以道路为边和路口为节点建模。我们应用渗透理论框架来分析网络结构上的碎片化过程。我们引入了两种策略来评估碎片化过程，即“目标随机化”和“吸引子引导”策略，它们使用两个中介中心性 (BC) 指标作为每条道路风险价值的代理。分析得出了四个主要发现。首先，苏黎世道路网络展示了一个相变，在 0.1-0.4 的中断边缘范围内损失了大约 90% 的功能。其次，2012 年稳健性指数的分布函数比 1955 年更稳健。第三，吸引子引导和目标随机中断策略在如何影响网络稳健性方面没有产生显着差异。第四，两个 BC 指标也对整体稳健性产生了轻微影响。未来的研究可以将时间分析扩展到更广泛的时间范围，并结合通勤出行，在碎片化分析中为道路风险分配一个新值。