1. Ph.D. Student, UNIC, Dept. of Civil Engineering, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829-516 Caparica, Portugal; and Visiting Ph.D. Student, School of Civil and Construction Engineering, Oregon State Univ., Corvallis, OR 97331-3212.
2. Assistant Professor, School of Civil and Construction Engineering, Oregon State Univ., 220 Owen Hall, Corvallis, OR 97331-3212 (corresponding author).
3. Associate Professor, School of Civil and Construction Engineering, Oregon State Univ., 220 Owen Hall, Corvallis, OR 97331-3212.
4. Lecturer, Nottingham Transport Engineering Centre, Univ. of Nottingham, Univ. Park, Nottingham NG7 2RD, U.K.; and UNIC, Dept. of Civil Engineering, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2829-516 Caparica, Portugal.