Abstract: The study is devoted to modeling of bus passenger carriers. Such companies are strictly regulated by regulatory authorities. Consequently, the financial performance of passenger carriers can change dramatically via. decisions of the regulator. Because of this, the adaptation of carriers to the requirements of the regulator is very important question. In this study, quite natural assumptions about the relationship between the main quantitative indicators of passenger carriers were formulated. This allowed us to derive a differential equation for the dynamics of the carriers profit under the conditions of constant external economic environment. For this equation, asymptotic estimates of the solutions and an estimate of the adaptation time carrier were obtained.