Model Application I: Measurement of Congestion Functions for Korean Highways

Travel cost, or in a more general sense, travel impedance, on a given highway link usually increases as the traffic flow increases.1 As traffic flow increases beyond a certain level, congestion takes place. In modeling a highway network with congestion effect, it is necessary to have a correct congestion function to account for increases in travel cost for the given highway environment. This highway environment includes driver characteristics, roadway conditions, and roadside activities. Different countries with distinctive demographic, economic, cultural, and behavioral characteristics might have unique congestion functions for their own environments.