Manley Ed
Centre for Advanced Spatial Analysis (CASA), University College London, Gower Street, London, United Kingdom.
PLoS One. 2015 May 26;10(5):e0127095. doi: 10.1371/journal.pone.0127095. eCollection 2015.
The emergence of large, fine-grained mobility datasets offers significant opportunities for the development and application of new methodologies for transportation analysis. In this paper, the link between routing behaviour and traffic patterns in urban areas is examined, introducing a method to derive estimates of traffic patterns from a large collection of fine-grained routing data. Using this dataset, the interconnectivity between road network junctions is extracted in the form of a Markov chain. This representation encodes the probability of the successive usage of adjacent road junctions, encoding routes as flows between decision points rather than flows along road segments. This network of functional interactions is then integrated within a modified Markov chain Monte Carlo (MCMC) framework, adapted for the estimation of urban traffic patterns. As part of this approach, the data-derived links between major junctions influence the movement of directed random walks executed across the network to model origin-destination journeys. The simulation process yields estimates of traffic distribution across the road network. The paper presents an implementation of the modified MCMC approach for London, United Kingdom, building an MCMC model based on a dataset of nearly 700000 minicab routes. Validation of the approach clarifies how each element of the MCMC framework contributes to junction prediction performance, and finds promising results in relation to the estimation of junction choice and minicab traffic distribution. The paper concludes by summarising the potential for the development and extension of this approach to the wider urban modelling domain.
大型细粒度出行数据集的出现为交通分析新方法的开发和应用提供了重大机遇。本文研究了城市地区路径选择行为与交通模式之间的联系,介绍了一种从大量细粒度路径数据中推导交通模式估计值的方法。利用该数据集,以马尔可夫链的形式提取道路网络节点之间的互连性。这种表示方式编码了相邻道路节点连续使用的概率,将路径编码为决策点之间的流量,而不是沿路段的流量。然后,将这个功能交互网络集成到一个经过修改的马尔可夫链蒙特卡罗(MCMC)框架中,该框架适用于估计城市交通模式。作为这种方法的一部分,主要节点之间数据衍生的链接会影响在网络上执行的定向随机游走的移动,以模拟起讫点行程。模拟过程得出道路网络上交通分布的估计值。本文介绍了针对英国伦敦的修改后的MCMC方法的实现,基于近700000条小型出租车路线的数据集构建了一个MCMC模型。该方法的验证阐明了MCMC框架的每个元素如何对节点预测性能做出贡献,并在节点选择和小型出租车交通分布估计方面取得了有前景的结果。本文最后总结了将这种方法开发和扩展到更广泛的城市建模领域的潜力。