Implications of hidden costs: Comparison of bitumen testing procedures

Traditional cost analyses used for process cost comparisons often ignore co sts (e.g., waste disposal, regulatory compliance, long-term liabilities) th at are lumped into general overhead but actually are incurred during the pr ocess. In this research, both a traditional cost analysis and a total cost assessment (which includes many often-neglected process costs) were perform ed on five potential methods of testing the bitumen composition of newly pa ved asphalt. In the past, the bitumen contact of asphalt pavement was deter mined by tests using toxic solvents; alternative, less polluting methods ha ve been developed that can replace the traditional solvent extraction metho d. In order to represent the uncertainties in the design and cost data (esp ecially the liability costs) for this cost comparison, fuzzy set theory was used. A traditional economic analysis that included only the capital and o perating and maintenance costs found that the most environmentally friendly process (ignition ovens) was only slightly less costly than two other opti ons. The cost of the ignition ovens and two other options were similar enou gh to be considered within the range of uncertainty for the analysis. Howev er. when the hidden costs related to the environmental, health, and safety aspects for a bitumen testing procedure were incorporated into the cost ana lysis, the cost comparison changed significantly; the most environmentally- friendly option, ignition ovens, was shown to be by far the least-cost opti on. Thus, incorporating hidden environmental costs into a cost analysis can have a significant impact.