Quebec public transportation authorities are having great financing difficulties. New financing sources are seldom and hard to establish into the actual economic context. In the early '70s, the French government has introduced the "versement-transport", a new tax dedicated to businesses being served by a public transportation system in order to make up the benefits issued from these infrastructures. The experience had been a great success. A subject's literacy has been done, either on that tax and on many aspects of public transportation tarification. Tarification based on marginal cost seems to have more advantages than the one based on average cost. Therefore, the research wanted to estimate the aptness of a new marginal cost based tarification imposed on businesses of a medium-size North-American city: Sherbrooke. The instrument used for the evaluation was the inquiry: interviews and scripted forms. The proposition of tarifying businesses for public transportation systems has not been popular, even with arguments that would lower some other production costs. On the other hand, they seemed to agree on the marginal cost based tarification principle. Transportation authorities must first try to change the perception of public transportation systems for businesses unless what every tarification attempt on them is nearly impossible.