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Real-driving emissions (RDE) testing with portable emissions measurement systems (PEMS) during the type approval and in-service conformity of light-duty vehicles was recently introduced in the European Union legislation. In this paper, three PEMS were compared with laboratory analyzers connected to the tailpipe and the dilution tunnel. The tests were conducted with two Euro 6 vehicles (one gasoline and one diesel) performing the World harmonized Light vehicles Test Cycle (WLTC) and a pre-recorded RDE cycle on a chassis dynamometer. The results showed that the differences of the PEMS gas analyzers compared to the laboratory references were typically within 2% for CO2 and 5% for NOx. The CO2 and NOx mass emissions were within 10% and 15%, respectively, with only a few exceptions. The exhaust flow rate measurements were within 10% at low speeds (urban conditions), and 5% at higher speeds. These results confirm the legislated permitted tolerances and the 2017 PEMS uncertainty estimates.

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The transportation sector is one of the main contributors to enhance quality of life, by providing accessibility to people, places and goods. On the other hand, it also contributes to the degradation of the environment, presenting high levels of energy consumption and pollutants emissions. Solutions to overcome this increasing trend have focused on the development of alternative vehicle technologies and fuels, innovative transport systems, and information and communication technologies. Users' behavior plays an essential role regarding the impacts of these solutions on reducing energy consumption and emissions. Over the years, rising attention has been given to behavior, both for light-duty and heavy-duty drivers, in particular to the effects of education, training, and feedback regarding driving performance on vehicle purchase, mobility patterns, and driving behavior. This paper aims at assessing the impacts of on-board devices that provide real-time feedback and eco driving training on bus drivers' behavior. Rodoviária de Lisboa S.A., a Portuguese bus passenger-transport company, uses since 2008 a data logger and a managing software platform, GISFROT, developed by the company, to collect real-time operation data and to identify undesirable driving behaviors. These devices indicate to the driver undesirable driving behavior events through a sound signal. Drivers also participate in annual in class training sessions on eco-driving techniques. The device is currently installed in 100 buses and approximately 600 drivers use these vehicles under regular daily operation, while driving in the Lisbon metropolitan area. An analysis of data collected from 2010 to 2013 was performed to characterize driving behavior of the sample of drivers. Two monitoring periods, a first one with sound feedback followed by a period without sound feedback, were considered. A comparison between periods was performed regarding the percentage of times drivers were in undesirable driving events such as hard brakes and hard accelerations, among others. This analysis also considered drivers characteristics (age and time working at company) and vehicle characteristics (bus age and type). The comparison between monitoring periods indicates that without sound feedback, inexperienced drivers and senior drivers tend to increase percentage of time in undesirable events, particularly * Catarina Rolim. Tel.when driving mini buses and articulated buses. These increases are mainly observable in extreme brakes and accelerations and hard stops, with rises between 8% and 291%.

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