Pedestrian metrics are needed for traffic engineers to get insights into pedestrian behaviour. Because pedestrian behaviour is very different from vehicle behaviour then, while we still need flow, speed, density and delay, we also have to understand how the counter-propagating flows, the less well-defined mixing of pedestrians arriving and leaving a flow from different directions and the variability in speeds within the flows all affect both the accuracy and usefulness of pedestrian metrics and their application to addressing real-world problems. These complexities of behaviour mean that simple detection has not been able to reliably measure, let alone give insights into, pedestrians, and it is only with the recent emergence of AI backed video systems that multiple actors can be tracked, and their characteristics determined. 10 years ago these types of tools were confined to research laboratories. Now they are commercially available products, and we need to consider how best to use them.
This paper will look at achievable pedestrian metrics and draw on academic research to talk about what we can now say about pedestrian movements under a range of densities, flows and speed conditions. It will offer metrics derived from the Cambridge trial site reported at JCT 2022 as the basis for assessing these pedestrian metrics and testing academic thinking on pedestrian behaviour. Their relevance to active travel schemes will be assessed.
Having reviewed the nature and relevance of these metrics the paper will talk about how these may inform the control of a signalised pedestrian crossing, extending work already reported by Starling and others at JCT in 2022. It will extend the idea that the advent of smarter detection leads to a partitioning of the signal decision-making process between detector and controller, with each processing the data it receives and the signal controller then bringing both parts together under its safety umbrella to determine when to next change the signals.
In this way we hope to inform the JCT audience about how they can start to align pedestrian monitoring and control with vehicle monitoring and control to help the transition toward better crossings and then a more fully integrated mobility management capability.