The automatic passenger counting system is used for recording passenger flows in public transport vehicles. It provides detailed information about the number of passengers who use the vehicle and passenger loads. Route parameters such as the line number, the route and its number, stop names combined with the date, time and information about passenger flows allow to carry out advanced statistical analyses to monitor line profitability and select optimal means of transport. This automatic passenger counting system installed in a public transport vehicle consists of sensors, recording equipment and a server. The operating elements of this system are sensors placed over doors that emit an IR beam downwards. Passengers, going through that beam, are recorded and information about it is automatically sent to a recording device. The data obtained, both about the number and the directions of passengers using the vehicle, is recorded and next transmitted from the vehicle to the central server, where is stored and analysed by software dedicated to a specific user. The main benefit of the automatic passenger counting system is decreasing costs, which results from the gained knowledge about how to match the means of transport and timetables better with the passenger flow. The reports and analysis, which were obtained based on the data from the system, support most management fields of the carrier, enabling the optimization of processes and their costs, from planning the means of transport and timetables, through using the data in marketing actions, to vehicle servicing.