Tae-Seok Yoo(Korea Expressway Corporation Research Institute, Research Fellow, 24, Dongtansunhwan-daero 17-gil, Hwaseong-si, Gyeonggi-do, Republic of Korea)
Corresponding author
Seong-Min Kim(Kyung Hee University, Professor, 1732, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do, Republic of Korea)