Optimal check up and replacement periods of variable message signs: A case of the Seoul metropolitan transportation center

Variable message signs (VMS) are one kind of traffic management facility installed following the "Guidelines on the Standard of Road Structures and Facilities." VMS are installed and operated within the Intelligent Transport Systems (ITS). However, existing VMS are operated and managed by designers or operators without any consistent criteria on check up and replacement periods. There has been very little research on check up and replacement periods of VMS. This study was to introduce a new methodology to estimate check up and replacement periods of VMS. This study reflected the actual VMS failure data and VMS and Portable Variable Message Signs luminance test results. Consequently, I hope that this study will be a useful reference for VMS and other ITS facilities.