In a competitive environment, satisfying the growing demand of customers for the quality of service of transport services, taking into account the economic interests of transport companies and service users is the most important task. Existing methods based only on the opinions of users do not fully take into account the interests of companies providing these services. To this end, the article analyzes the qualitative indicators of customer service provided by transport companies when providing them with various services. It has been established that the cost of organizing the service, the (lost) income, and the time lost by customers depend on the quality of service. This analysis is based on the queuing theory model. A method is proposed for determining the optimal value from an economic point of view of indicators of the quality of customer service. The method is based on minimizing a generalized indicator – reduced costs. This indicator takes into account, on the one hand, the interests of the company and, on the other hand, the interests of service users. The results obtained allow companies to choose the quality of customer service indicator and its optimal value for the provision of various services.