Infrastructure Planning and Management Vol.40 (Special Issue)
A STUDY ON SECULAR CHANGE OF NON-CONGESTED SPEED OF INTERURBAN EXPRESSWAYS
2023 Volume 78 Issue 5 Pages I_839-I_852
Details
2023 Volume 78 Issue 5 Pages I_839-I_852
Previous studies have shown that the traffic performance of interurban expressways declined during the past 14 years from 2003 to 2016. However, it is not clear how it decreased during the same period. In addition, there are few studies showing the secular change of the observed non-congested speed by traffic volume, and the change in speed distribution is unknown. In this study, after analyzing the non-congested speed by traffic volume on interurban expressways for 24 years from 1996 to 2019, it was clarified that it started to decrease from 2001 to 2008, and the free flow speed distribution shifted to a lower region. In addition, the speed reduction is large for constrained flow at high flow condition, and the speed decreased more over time especially for large vehicles.
