Over the last years, the exponential growth of air traffic has led to an increase in aviation-related negative externalities, raising the issue of sustainable growth in air transport to the forefront of policymaker and national government debates. One of the strategies designed to reverse this trend is to enable modal shift toward greener transport modes where technically possible. Our research quantifies, at a pan-European level, the possible impact of a policy of cancellations of short-medium-haul air routes that are currently effectively served by alternative transport modes, and mainly by high-speed rail. Following recently introduced policy initiatives, we analyze route substitutability based on not only the increase in travel time faced by passengers due to the enforced modal shift, but also the corresponding change in their generalized travel costs. At a macro-European level, our analysis reveals that about 26.5 million (3.02% of intra-European) offered seats may be cancelled and substituted with alternative trips without any significant increase in travel time for passengers. The French domestic market and flag carrier Air France lead the standings both in terms of the number of substitutable offered seats and potential CO₂ savings. Moreover, analyzing the impacts at the regional level, we outline that this policy would preserve disadvantaged regions by placing the burden of reducing emissions from aviation mainly on areas already efficiently served by alternative transport modes. Overall, the replacement of short-medium haul routes would undoubtedly mark a step toward meeting medium-long-term targets of greenhouse gas emission reduction. Eventually, we discussed a number of key issues that policymakers need to address for a successful and not-myopic implementation of the policy.

在过去几年中，空中交通的指数增长导致与航空相关的负外部性增加，将航空运输的可持续增长问题提升到政策制定者和国家政府辩论的前沿。旨在扭转这一趋势的策略之一是在技术上可行的情况下实现向更绿色运输方式的模式转变。我们的研究在泛欧层面量化了取消中短途航线政策的可能影响，这些航线目前由替代运输方式有效服务，主要由高速铁路提供服务。继最近推出的政策举措之后，我们不仅基于强制模式转变导致乘客出行时间增加，分析了路线替代性，而且他们的一般旅行费用也相应变化。在宏观欧洲层面，我们的分析显示，大约 2650 万个（占欧洲内部的 3.02%）提供的座位可能会被取消并代之以替代旅行，而不会显着增加乘客的旅行时间。法国国内市场和旗舰航空公司法航在可替代座位数量和潜在 CO 方面均处于领先地位₂储蓄。此外，通过分析区域层面的影响，我们概述了这项政策将通过将减少航空排放的负担主要放在已经由替代运输方式有效服务的地区来保护弱势地区。总体而言，中短途航线的更换无疑标志着朝着实现温室气体减排中长期目标迈出了一步。最后，我们讨论了政策制定者为成功且不短视地实施政策而需要解决的一些关键问题。