Using multiple hybrid spatial design network analysis to predict longitudinal effect of a major city centre redevelopment on pedestrian flows

Abstract

Predicting how changes to the urban environment layout will afect the spatial distribution of pedestrian fows is important for environmental, social and economic sustainability. We present longitudinal evaluation of a model of the efect of urban environmental layout change in a city centre (Cardif 2007–2010), on pedestrian fows. Our model can be classed as regression based direct demand using Multiple Hybrid Spatial Design Network Analysis (MH-sDNA) assignment, which bridges the gap between direct demand models, facilitybased activity estimation and spatial network analysis (which can also be conceived as a pedestrian route assignment based direct demand model). Multiple theoretical fows are computed based on retail foor area: everywhere to shops, shop to shop, railway stations to shops and parking to shops. Route assignment, in contrast to the usual approach of shortest path only, is based on a hybrid of shortest path and least directional change (most direct) with a degree of randomization. The calibration process determines a suitable balance of theoretical fows to best match observed pedestrian fows, using generalized cross-validation to prevent overft. Validation shows that the model successfully predicts the efect of layout change on fows of up to approx. 8000 pedestrians per hour based on counts spanning a 1 km2 city centre, calibrated on 2007 data and validated to 2010 and 2011. This is the frst time, to our knowledge, that a pedestrian fow model with assignment has been evaluated for its ability to forecast the efect of urban layout changes over time.