This study investigates the impact of a ban on short-haul flights in Europe on transfer passengers and CO2 emissions, focusing on both time-based and distance-based bans. Employing a route assignment analysis of a base scenario of Europe with an optimal High-Speed Rail (HSR) netwerk, compared with various scenario's of a ban. Results reveal that the impact of the ban on CO2 emissions is influenced by transfer passengers, primarily due to their average detour distance. The effects on different European hubs vary based on their geographical and operational characteristics. The findings suggest that a time-based ban could contribute to CO2 emission reductions, but more research is needed on the effects of the ban within the current HSR network in Europe. It is clear that the ban will impact hubs, and future research should examine how this will affect connectivity and economies in different regions.