Urban freeway, which is defined as a divided highway with full control of access and two or more lanes for the exclusive use of traffic in each direction, means a high-speed and high-volume network for travel in the big city. However, most of the urban freeways are undergoing a severe traffic congestion because of increased traffic concentrated on the urban freeway. Thus, the purpose of this study is to investigate the real-time traffic characteristics, analyze the relationships between the real-time traffic characteristics, and finally construct the travel delay predictive models on the merge sections in the most congested urban freeway interchange in Busan city.
From the traffic characteristic analyses, construction and verification for the delay predictive models on the merge sections of the urban freeway interchange under the study, the following conclusions were drawn
i) Traffic flow showed a big difference depending on the time periods in the urban freeway interchange. Particularly more traffic were concentrated on the urban freeway interchange in the daytime period when compared with the nighttime period.
ii) Traffic flow also showed a quite difference depending on the travel directions in the urban freeway interchange. Particularly more traffic were concentrated on the urban freeway interchange in the inbound direction when compared with the outbound direction.
iv) The delay predictive models showed a higher explanatory power in the inbound direction and the daytime period, but a lower explanatory power in the outbound direction and the nighttime period.