Abstract
This paper examines the relationship between the location of interchanges and the travel time to a fixed destination and the nearest interchange. First, we formulate a simple model in which an expressway and local roads are assumed to be a straight line and a continuous plane respectively. Then, we analyze how introducing a smart-interchange affects the travel time. The smart-interchange is an interchange which is only for electronic toll collection system (ETC). The model shows that introducing a smart-interchange is effective in the region where the spacing between adjacent interchanges is large and the speed on local roads is low.
