Social acceptance of low-carbon transport technologies is a crucial but frequently underrepresented dimension in energy system optimization models (ESOMs), despite its potential relevance for the design of effective decarbonization policies. This study examines the role of social acceptability in the transition of the European Union transport sector toward climate neutrality by integrating behavioral factors into the open-source ESOM TEMOA-Europe. In particular, social acceptability is represented through technology-specific hurdle rates, used as proxies for perceived risk and financing barriers, alongside assumptions on declining investment costs for low-carbon vehicle technologies. Four scenarios are developed and compared: (i) a Base scenario, (ii) a scenario with reduced hurdle rates for battery electric and fuel-cell vehicles, (iii) a CostSC scenario with lower investment costs for green truck technologies, and a Net0 scenario (iv) imposing a binding net-zero emissions constraint by 2050. The analysis evaluates these scenarios based on technology uptake, system costs, CO2 emissions, and critical raw material requirements. Results show that, in the passenger car sector, lower perceived risk can substantially accelerate electrification and achieve emissions reductions comparable to those obtained under stringent regulatory constraints, in some cases at lower overall system cost. By contrast, the freight sector appears considerably less responsive to such demand-side measures, indicating the need for stronger regulatory intervention. The findings also highlight that deep transport decarbonization implies a substantial increase in demand for critical raw materials, reinforcing the importance of complementary recycling and supply-chain policies.
