The impact of integrated street design on flow-density curves: An empirical analysis for motorised and pedestrian traffic

Abstract

Urban street design has been influenced by a shift in thinking in recent years, which advocates for more equal treatment of all road users. This has effected a move away from the traditional concept of segregation between motorised traffic and pedestrians, and towards greater integration of the two. In practice, the new approach usually manifests itself in more pedestrian-friendly layouts with wider footways, fewer protective guardrails and lower (or even no) kerbs. Following-on from previous research on the topic, this study concentrates on the impact of such designs on the fundamental relationships between flow, density and speed for both motorised traffic and pedestrians, offering empirical evidence. Video footage from London’s South Kensington site during periods before and after its conversion from a conventional layout to a more integrated pedestrian-oriented design is used to extract relevant measurements and derive and compare flow-density curves. The findings indicate stabler and more relaxed driving and walking behaviour post-redevelopment, which are in addition to effects arising from changes in the demand and supply. This suggests that both types of road users stand to benefit from integrated street design elements.