This article is about real-time data collection possibility in public transport system. It means, that data about real number of passengers in the system have to be collected in real-time conditions and transferred for further analysis and monitoring. As well as an easy passenger counting method for sustainable public transport system is offered in the article. Hopefully, current article helps to understand better, how to get real input data for passenger flow analysis in public transport system, as well as how to find the best solution for data transferring for making public transport system more sustainable and how to find out actual flows of passengers in the system. It is clear, that actual number of passenger in public transport system at each moment of time is vitally significant information to know, and this research offer solutions how it is possible to solve the task. In this paper author offers to use simple calculations for passenger counting and a method of photogrammetry for real-time data collection for further passenger flow studies and analysis.