In the study the results of vehicle emission tests in road conditions were presented as only then information on real vehicle emissions could be obtained. The tests were carried out on sections of tens to hundreds kilometers in different road conditions. They include information on emissivity of vehicles in exploitation and deal with real conditions of vehicle movement. In order to measure concentration of toxic compounds a mobile analyzer for toxic tests SEMTECH DS by SENSORS Inc. was used. It is possible to add data sent directly from the vehicle diagnostic system to the central unit of the analyzer and make use of localization signal GPS. In the study the results of vehicle emission tests in road conditions were presented as only then information on real vehicle emissions could be obtained. They include information on emissivity of vehicles in exploitation and deal with real conditions of vehicle movement