Since Gyeongin expressway was firstly built between Seoul and Incheon in Korea in 1968, around 32 routes of expressways have built based on the metropolitan cities including Seoul and Busan in Korea until now open. However, most expressways in Korea are suffering from transportation problems with increased traffic volumes and high proportions of heavy vehicles in the traffic, because they are based on a few metropolitan cities and are not properly linked with the small cities in the country. Thus, it is strongly needed to improve the expressway traffic management system with traffic characteristics-related studies at the basic expressway segments.
The purpose of this study is to identify the lane traffic characteristics(volume, speed, and density) at the 8-lane basic segments of Gyeongbu and Namhae expressways, conduct correlation analysis between lane-based space mean speed and planning time by travel time reliability at the basic expressway segments, and finally select the most appropriate regression model between the space mean speed by lane and the planning time by travel time reliability at the basic expressway segments.