Variability of commuters’ bus line choice: an analysis of oyster card data

Abstract

A hyperpath can be defined as a set of attractive lines identified by the passenger, each of which might be the optimal one from the current stop, depending on lines’ arrival time, frequency, cost etc. This concept can lead to complex route choice and has been a fundamental assumption in most transit assignment models, despite few evidence whether passengers’ indeed select such complex strategies. This research uses time series smart card data from London to investigate flexibility in buses chosen by morning commuters. The analysis is based on n-step Markov models and proposes that the variations in bus lines taken by passengers who supposedly travel between the same OD pair every morning over several days should reflect the set of paths included in an (optimal) hyperpath. Our hypothesis is that a large variation in bus lines over days indicates a complex hyperpath whereas a passenger who takes the same line every morning does not consider many alternatives. Our results suggest that there is indeed significant variation in bus lines chosen, possibly in accordance with the theory of hyperpaths in networks with uncertainty.