The type approval tests of vehicles with internal combustion engines increasingly include issues regarding the assessment of ecological indicators in real traffic conditions. This is done with the help of specialized equipment from the PEMS (Portable Emissions Measurement Systems) group. This requires not only a series of test procedures, but also assembly of technically advanced equipment along with the proper preparation of the vehicles exhaust system. Currently, activities are being carried out to develop solutions for non-invasive assessment of ecological indicators from moving vehicles. The article discusses these types of solutions, at the same time indicating their strengths and weaknesses. Also presented are pollutant emission tests in real operating conditions that will be used to develop a modular exhaust emission gateway. The result of the analysis was to indicate the development directions of methods for exhaust emission assessment from vehicles in motion.