Cost benefit analysis is the conventional method of evaluating automobile transportation improvements. This study examined traditional automobile evaluation methods and applied the same techniques to bicycle transportation projects. Cost data from recent research is summarized and eleven costs (five internal and six external) were estimated. The cost estimates are used to calculate automobile and bicycle costs per mile of travel. A case study of a hypothetical corridor is used to demonstrate how the transportation costs can be applied to specific planning problems. The case study explores what effect shifts in modal distribution would have on the cost effectiveness of automobile and bicycle alternatives. The findings of the study begin to question the underlying premises of traditional cost benefit analysis in transportation projects. The study suggests that conventional analysis is fundamentally flawed and biased toward automobile transportation. / Department of Urban Planning