The lack of cycling infrastructure is a major deterrent to cycling for transportation in the U.S., yet planners and engineers may lack the tools to assess and communicate the potential network impacts of proposed cycling infrastructure. Without these tools, cycling infrastructure may be built ad hoc or where it is politically convenient, instead of where it would be most effective at improving mobility, accessibility, and the actual and perceived safety of cycling. To address these problems, this research outlines a framework for assessing new and existing infrastructure through BikewaySim. BikewaySim is an open-source shortest path model that uses link impedance functions to account for cyclists' preferences for link attributes (e.g., presence of a bike lane, flat terrain, traffic volumes, traffic speeds) and Dijkstra's algorithm to find the least impedance path between any origin-destination pair. To demonstrate the framework, the shortest path is found between 28,392 potential origin-destination pairs for a small study area in Atlanta, GA to assess the impacts of two infrastructure projects. Two impedance functions are demonstrated. The first is based on travel time, while the second uses travel time and example attribute impedances. From the solved shortest paths, percent detour, change in impedance, and link betweenness centrality are calculated, and bikesheds, selected routes, and link betweenness centrality are visualized. Results demonstrate that BikewaySim can effectively visualize potential network improvements from cycling infrastructure and has additional applications for trip planning. Future research will focus on calibrating link impedance functions with GPS trace data showing revealed preferences and surveyed response data on user preferences for cycling infrastructure.

中文翻译：

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使用最短路径路由来评估自行车网络

缺乏自行车基础设施是美国骑自行车交通的主要障碍，但规划者和工程师可能缺乏评估和传达拟议自行车基础设施潜在网络影响的工具。如果没有这些工具，自行车基础设施可能会临时建造或在政治上方便的地方建造，而不是在改善流动性、可达性以及自行车的实际和感知安全性方面最有效的地方。为了解决这些问题，本研究概述了通过 BikewaySim 评估新的和现有基础设施的框架。 BikewaySim 是一个开源最短路径模型，它使用链路阻抗函数来考虑骑车者对链路属性的偏好（例如，自行车道的存在、平坦的地形、交通量、交通速度），并使用 Dijkstra 算法来查找最小阻抗路径任何出发地-目的地对之间。为了演示该框架，我们在佐治亚州亚特兰大的一个小型研究区域的 28,392 个潜在出发地-目的地对之间找到了最短路径，以评估两个基础设施项目的影响。演示了两个阻抗函数。第一个基于行程时间，而第二个使用行程时间和示例属性阻抗。根据求解的最短路径，计算绕行百分比、阻抗变化和链路介数中心性，并将自行车棚、选定路线和链路介数中心性可视化。结果表明，BikewaySim 可以有效地可视化自行车基础设施的潜在网络改进，并具有用于行程规划的其他应用程序。未来的研究将侧重于利用 GPS 跟踪数据来校准链路阻抗函数，这些数据显示了用户对自行车基础设施偏好的揭示偏好和调查响应数据。