Quantification of the Effect of ITS on CO2 Emissions from Road Transportation

The paper presents an overview of the final results of the 7FP ICT-EMISSIONS project that developed and validated a novel methodology and tool set to evaluate the impact of ICT-related transport measures on mobility and CO2 emissions of vehicle fleets under real-world conditions. The methodology combines traffic and emission modelling at micro and macro scales. The integration of these scales is an important feature because a measure to influence the behaviour of single vehicles may have an impact on the whole network, while traffic management at the network level may influence the behaviour of the single vehicles. The paper presents results of a number of ITS systems including Variable Speed Limit (VSL), Green Navigation (GN), Urban Traffic Control (UTC), Ecodriving and Adaptive Cruise Control Systems (ACC). These measures have been tested for concrete application cases implemented in the cities of Turin, Madrid and Rome. Starting point were real-world data collected by means of floating cars. The investigations have taken into account different penetration rates of ICT measures, as well as different traffic conditions (e.g. free flow, congested). Each case has been modelled for the current and at least on future fleet composition. The results indicate that ITS are overall able to contribute to CO2 emissions reduction by several percent points; the effects, nevertheless, are different depending on local conditions. The CO2 benefit is also found to be constrained by the penetration rates of the on-road ITS equipped vehicles: as this share increases a maximum is reached at up to 50% penetration rate and under non-congested conditions.