Commuter dependence on expressways when travelling to work

Traffic congestion is a serious problem in the Seoul metropolitan area in Korea, as the city has sprawled drastically over the past several decades. Although the area has a considerable length of expressways, commuters travelling on them ironically suffer from recurrent traffic congestion. The present study focused on the factors that lead commuters to depend on expressways regardless of the disadvantages in terms of travel costs and even travelling times. The impact of commuters' behavioural or attitudinal latent propensities on determination of their usual route for their commute to work was investigated based on a binary logit choice model. Route- and individual-specific variables, which have been widely adopted in conventional route choice studies, were also included in the model. A total of 522 commuters participated in the survey and provided actual information of the routes they used to travel to work. The results showed that behavioural or attitudinal latent determinants other than travel times and costs also contributed to commuters' dependence on expressways.