Journal of Infrastructure Systems, 19(1), 25-35. Author's accepted manuscript http://dx.doi.org/10.1061/(ASCE)IS.1943-555X.0000103 Author note to the article of record: Assistant Professor, Defense Resources Management Institute, Naval Postgraduate School, 699 Dyer Rd., Bldg. 234, Monterey, CA 93943; formerly, Doctoral Candidate, School of Industrial and Systems Engineering, Univ. of Oklahoma, 202 W. Boyd St., Room 124, Norman, OK 73019 (corresponding author). E-mail: camacken@nps.edu