Expressways mean the primary arterial highways with a high level of efficiency and safety. However, Gyeongbu and Namhae expressways connected with Busan ports are showing travel time delay by increased traffic including the medium/ large-sized vehicles of about 20% compared to those of about 13% regardless of the peak periods. This study, thus, intends to analyze lane traffic characteristics in the basic 8-lane segments of the above-mentioned expressways, compute the planning and buffer times based on travel time reliability, find the lane speed showing a higher correlation with planning time between the lane speeds in the basic 8-lane segments, and finally suggest a correlation model for predicting the planning time in expressways.

1. Introduction
2. Analysis of traffic characteristics
3. Correlation Analysis of Usi and TP
4. Model Development and Verification
5. Conclusion
References

• Tae-Gon Kim(Department of Civil Engineering, Korea Maritime and Ocean University) Corresponding author