This investigation analyzes the feasibility of using a traffic simulator, and in particular the open source software SUMO, to obtain speed profiles under Real Driving Emission (RDE) tests to be used for the modeling and the optimization of conventional and hybrid electric powertrains. The first step of the investigation is the setup and amendment of the SUMO software to reproduce real driving emissions tests performed in Lecce with a start&stop Class 3b diesel vehicle equipped with a Portable Emission Measurement System (PEMS) in spring-summer 2017. Due to the high cost of using a PEMS instrumentation and being the measurement of pollutant emissions optional in the present investigation, the experimental campaign is extended here with the help of a OBD-II scanner whose usefulness to obtain the real world levels of fuel consumption and CO2 with reduced costs and times is proved in literature. All the experimental tests of this second step are performed on an optimized route that was identified in Lecce for the execution of Real Driving Emissions tests required by the new European Commission Regulations for vehicle certification in a previous investigation of the authors. In the third part of this study, the data acquired in the experimental campaign are used to validate the use of traffic model with respect to different vehicles and traffic conditions. Finally, the traffic simulator is integrated with an open source tool for the modeling and the optimization of conventional and hybrid electric power systems to show its potentiality for the estimation and minimization of CO2 emissions over RDE driving conditions.