Public infrastructure owners are increasingly soliciting BOT arrangements to deliver needed infrastructure facilities. Such arrangements potentially preserve a public owner's capital capacity for allocation to projects that cannot support themselves by essentially ‘pulling’ projects from the private sector. Before soliciting these arrangements, however, owners should independently evaluate a project's economic viability to fully appraise the issues and variables involved. Unfortunately, project analysts often apply evaluation methods without regard for their assumptions and limitations. A case study of a toll road project in the USA provides the basis for examining the assumptions behind both traditional and option valuation models. The case demonstrates the use of an option pricing model to augment traditional project evaluation by capturing strategic considerations, in this case the value of project deferment. The presentation illustrates that the selection of a valuation model depends critically upon the characteristics of a project's variables and that informed judgment remains an integral part of the decision‐making process.