Using principal curves to analyse traffic patterns on freeways

Einbeck, Jochen; Dwyer, Jo

Abstract

Scatterplots of traffic speed versus flow have caught considerable attention over the last decades due to their characteristic half-moon like shape. Modelling data of this type is difficult as both variables are actually not a function of each other in the sense of causality, but are rather jointly generated by a third latent variable, which is a monotone function of the traffic density. We propose local principal curves as a tool to describe and model speed-flow data, which takes this viewpoint into account. We introduce the concept of calibration curves to determine the relationship between the latent variable (represented by the parametrization of the principal curve) and the traffic density. We apply local principal curves to a variety of speed-flow diagrams from Californian freeways, including some so far unreported patterns

Citation

Einbeck, J., & Dwyer, J. (2011). Using principal curves to analyse traffic patterns on freeways. Transportmetrica, 7(3), 229-246. https://doi.org/10.1080/18128600903500110

• Journal Article Type: Article
• Publication Date: May 1, 2011
• Deposit Date: Nov 9, 2010
• Publicly Available Date: Nov 11, 2010
• Journal: Transportmetrica
• Print ISSN: 1812-8602
• Electronic ISSN: 1944-0987
• Publisher: Taylor and Francis Group
• Peer Reviewed: Peer Reviewed
• Volume: 7
• Issue: 3
• Pages: 229-246
• DOI: https://doi.org/10.1080/18128600903500110
• Keywords: Fundamental diagram, Capacity, Local principal curves, Smoothing.
• Public URL: https://durham-repository.worktribe.com/output/1537477
• Publisher URL: http://www.maths.dur.ac.uk/~dma0je/Papers/einbeck_dwyer_transportmetrica10.pdf