ABSTRACT. The addition of output variation benefits to the users' surplus generated by transportation improvements has been subject to debate, and no agreement has been reached. In this paper, the problem is restated at the level of the origins of transportation demand, which can be derived from the information provided by the economic activity. It is shown that a competitive productive environment makes the transportation consumers' surplus exactly equal to the net economic benefits provoked in the products' markets; however, when monopolistic production prevails, the users' surplus may not reflect the benefits to the economy with accuracy. Mixed conditions are also explored and the role of final products' demand elasticity is highlighted. Different styles of welfare analysis are recommended for different market conditions.