We would like to thank the Mershon Center at Ohio State University and the Centre for Infrastructure Performance and Reliability at the University of Newcastle, Australia for travel and research support. Mark Stewart also appreciates the financial support provided by the Australian Research Council including a recent five-year ARC Professorial Fellowship which will allow this work to be continued. John Mueller appreciates the financial support from an Ohio State University Distinguished Scholar Award. A special thanks to Dr. Rick Herrmann, Director of the Mershon Center, for supporting Professor Stewart’s visiting fellowships to the Mershon Center. We are grateful for helpful comments from David McBride and Judy Mueller. Thanks, too, to Jenny Wolkowicki and Ashwin Bohra for excellent work in expediting the production process.