Enabling technologies assessment for reducing Italian LPT emissions on short and long-term time frames

The international policies on energy transition and sustainable development for mitigating global warming aim to limit the rise in global temperatures to 1.5 °C and consequently to outline a transition towards zero greenhouse gas emissions (GHG) by 2050. Vehicular traffic is responsible for about 30% of the total direct GHG, making it one of the most critical sectors. The achievement of net zero GHG emission goal in transportation sector relies in both improving the energy efficiency of the actual vehicles and promoting more efficient modes of transport. In this context, the development and enhancement of local public transport (LPT) systems represent a key point for future mobility, due to the reduced consumption and emissions per unit of transported passenger. As a result, public transport companies need to take rapid action to modernize their fleets, which currently consist mostly of diesel buses, by introducing vehicles and fuels with a lower environmental impact. With reference to the bus transit component of LPT, this article provides an assessment of vehicle and energy enabling technologies for emission mitigation in Italian LPT in a short (2030) and medium-long term (2050) application time frame, in accordance with the EU policy objectives contained in the "Fitfor55" proposal. The study shows that achieving GHG reduction targets requires the use of a mix of technological solutions, both vehicular and energy. Some of them, reduced environmental benefits, are immediately exploitable, in terms of maturity and cost-effectiveness, while others, more promising, are based on less mature technologies, now more expensive, and on the use of energy vectors produced from renewable sources, for which a significant research and development effort is required.