The daily dynamic potential accessibility by car in London on Wednesdays

The map presented in this paper shows the effect of congestion on daily accessibility in the London metropolitan area on Wednesdays. Because of its dynamic nature, it is challenging to both calculate the effects of this phenomenon and to represent it clearly on simple maps. Although we can use many traditional techniques for this purpose, they are usually static, and they may lose some essential information on the effects studied. In this paper, we used two cartographic techniques rarely used in accessibility studies – cartograms and 3D maps, which we believe can achieve a more striking representation in static and animations of both the traffic-induced spatial distortion and the accessibility levels obtained. The results are presented in two animated maps and some snapshots of them – static maps. Both types of maps reinforce each other: Together, they can properly show the direct space–time link between congestion and accessibility, and can, therefore, give a more detailed overview of the consequences of this phenomenon.

本论文展示的地图，呈现了周三时段伦敦大都市区内交通拥堵对日常出行可达性的影响。鉴于拥堵现象的动态特性，精准测算其影响并在简易地图上清晰展示该影响，均存在不小挑战。尽管可借助诸多传统制图技术实现此目标，但这类技术多为静态形式，往往会丢失所研究的拥堵影响中的部分核心信息。本研究采用了两种在可达性研究中较为少见的制图技术——变形地图（cartograms）与三维地图，我们认为二者可在静态图像与动画中更出色地展现交通引发的空间畸变与所得出的可达性水平。研究结果通过两幅动画地图及其静态截图（即静态地图）进行呈现。这两类地图可互为补充：二者结合能够准确呈现拥堵与可达性之间直接的时空关联，从而可更为详尽地展现该现象带来的各类后果。