Expressway was firstly opened between Seoul and Incheon at the end of the 1960’s, and 32 routes of expressway have been constructed in Korea since then. Particularly, Gyeongbu and Namhae expressways were built for transporting the import and export cargoes through the port of Busan in the early 1970s. Passenger cars were sharply increased with the rapid economic leap after the Seoul Olympics in 1988, and expressways were steadily constructed between the metropolitan and local areas. Most expressways are however suffering from transportation problems with increased automobiles and high proportions of heavy vehicles, because urban development were accelerated with the population concentration on the urban areas. Thus, it is strongly needed to study the travel characteristics for improving traffic management system in expressways operated by the designated lane system.
The purpose of this study is to identify the lane travel characteristics at the 8-lane basic segments of Gyeongbu and Namhae expressways, analyze correlative characteristics between lane-based travel characteristics at the basic expressway segments, and finally construct the most appropriate predictive models of mean travel time and delay in expressways.
From the travel characteristic analysis, correlation analysis between the lane-based travel characteristics, and modeling of mean travel time and delay in expressways, the following conclusions were drawn:
ⅰ) Traffic analyses appeared to show a distinct difference in travel characteristics by the direction, the lane, the day of the week and the time of day. So, we concluded that the freeway traffic management system(FTMS) such as advanced traveler management systems/advanced traveler information systems(ATMS/ATIS) by the direction, the lane, the day of the week and the time of day could be very effective in improving the effectiveness of expressways operated by the designated lane system.
ⅱ) Correlation analyses appeared to show a high correlation between the lane-based segment mean speed and mean travel time, and also the lane-based delay and mean delay. So, we concluded that the segment mean speeds at the 2nd and 3rd lanes could have the highest correlation with the mean travel time, and also the delay at the 3rd lane had the highest one with the mean delay regardless of the direction in expressways operated by the designated lane system.
ⅲ) Regression models appeared to show the highest validity between the predicted mean travel time and the calculated one, and between the predicted mean delay and the calculated one. So, we concluded that multiple linear function by the segment mean speeds at the 2nd and 3rd lanes could be more effective in predicting the mean travel time and simple linear one by the 3rd lane delay could be more effective with the high explanatory power and validity at the 95 percent confidence level.