1. Professor, Centre for Infrastructure Performance and Reliability, School of Engineering, Univ. of Newcastle, Callaghan, NSW, 2308, Australia (corresponding author). E-mail: mark.stewart@newcastle.edu.au
2. Graduate Student, Centre for Infrastructure Performance and Reliability, School of Engineering, Univ. of Newcastle, Callaghan, NSW, 2308, Australia.
3. A. P. and Florence Wiley Chair Professor and Dept. Head, Dept. of Civil Engineering, Texas A&M Univ., College Station, TX 77843-3136.