*1.2. Review of the Existing Literature*

There is a growing interest in research about EDV applications for road freight transport; with most of the research assessing the performance of EDVs compared with internal combustion engine vehicles (ICEVs) from energy consumption, CO2 emissions and/or cost perspectives.

On a single-vehicle basis, Zhao et al. [35] estimated energy consumption, CO2 emissions and cost performance for a HEV, a BEV and a FCEV and compared them with a diesel-fueled ICEV for Class 8 trucks in the United States. Lee et al. [36] estimated energy consumption, GHG emissions and total cost of ownership (TCO) for ICEV and BEV urban delivery trucks. Lajunen [37] evaluated energy consumption for HEVs and compared them with ICEVs for HDVs in Finland. Gao et al. [38] assessed several energy consumption reduction technology measures for ICEVs and HEVs for Class 8 trucks in the United States. Lebeau et al. [39] assessed the cost-effectiveness of BEVs for freight transport in Brussels, Belgium, focusing on light commercial vehicles and quadricycles. Zhao et al. [40] assessed energy consumption and GHG emissions for ICEVs, HEVs and BEVs for Class 3–5 delivery trucks in the United States. Kast et al. [4,6] assessed the performance of FCEVs in the MDV and HDV segments in the United States. Sen et al. [31] estimated life cycle GHG and air pollutant emissions, costs and externalities for ICEVs, HEVs and BEVs for Class 8 trucks in the United States. Lee and Thomas [31] evaluated energy consumption, water use, GHG and air pollutant emissions for ICEVs, HEVs and BEVs in medium-duty trucks in the United States. Zhao and Tatari [41] evaluated energy consumption and GHG emissions for ICEVs, HEVs and plug-in hybrid electric vehicles (PHEVs) for refuse trucks in the United States. Zhou et al. [42] assessed life cycle GHG emissions and TCO for ICEVs and BEVs for Class 6 trucks in Toronto, Canada.

Other studies assessed the role of EDVs in road freight transport on a fleet basis without considering vehicle stock turnover. Davis and Figliozzi [43] assessed the economic competitiveness of ICEVs and BEVs for MDVs in the United States. Wikström et al. [28] evaluated BEVs and PHEVs for road freight transport in Sweden from technological and social perspectives. Zhao et al. [27] estimated the optimum penetration of HEVs and BEVs in a commercial delivery fleet of MDVs in the United States. Christensen et al. [44] studied the suitability of BEV introduction for road freight transport in LDVs and HDVs in Germany and Denmark. Though valuable, these studies did not capture the dynamics of technology diffusion in the road freight vehicle fleet.

Regarding studies on a fleet basis that considered vehicle stock turnover, Li et al. [45] estimated the most cost-effective pathways to reduce oil consumption in road freight transport in China, considering ICEVs and HEVs; without considering BEVs and FCEVs. Askin et al. [26] analyzed the factors that can influence deployment of advanced technologies in HDVs in the United States, considering natural gas-fueled ICEVs and diesel-fueled HEVs; without considering BEVs and FCEVs. Oshiro and Masui [46] studied the impact of EDV diffusion in road transport in Japan, focusing on HEVs and FCEVs as powertrain options for HDVs; without considering fuel consumption evolution in time and cost. Fridstrøm [47] evaluated the role of EDVs in GHG emissions reduction in road transport in Norway, including freight transport; without considering the impact on cost. Talebian et al. [47] studied the potential of BEVs and FCEVs to reduce GHG emissions in road freight transport in British Columbia, Canada; without considering the impact on cost. Mullholland et al. [48] assessed the CO2 emissions reduction potential of HEVs and BEVs in global road freight transport; without considering FCEVs and the impact on cost.

The main characteristics of the most relevant studies regarding powertrain electrification in road freight transport are summarized in Table 1. No research was found in the reviewed literature that assesses the potential of powertrain electrification to reduce CO2 emissions in road freight transport and the associated cost, considering the dynamics of technology diffusion.


**Table 1.** Main characteristics of previous studies regarding powertrain electrification in road freight transport on a fleet basis.
