As rational economic agents we all, consciously or unconsciously, undertake a form of cost benefit analysis when deciding on a particular course of action. As we consume a product we attempt to extract as much marginal utility from it as possible. Generally we will stop consuming when there is a negative impact on our well being. Think about gulping down that ice cold water after a hot sports day race; the criteria for giving the green light to certain infrastructure projects is similar, the difference is that the social costs and benefits must be considered. This leads us to the normative and positive aspect of appraising such projects. Are such projects, as the ones below, given the go ahead based on political persuasion or rational economics, or are these one in the same?