Airlines continue to maintain flight frequencies despite the competitiveness of high-speed rail

The liberalisation of the high-speed rail market in Spain in 2020 enabled an increase in passengers compared with its competitor: air transport. Airlines responded to this rise in competition by reducing seat supply by between 10% and 16%, but maintained flight frequencies to avoid compromising connectivity at air hubs. This is the main conclusion of a paper authored by researchers from the Universitat Oberta de Catalunya (UOC), the University of Barcelona (UB) and the Autonomous University of Barcelona (UAB).

The open-access article explains that the European Union supports high-speed rail as a sustainable mode of transport, and highlights market liberalisation as one way to promote it. Spain is one of the few countries where this measure has been implemented. In 2020, operators were liberalised on the main corridors: Madrid–Barcelona, Madrid–Valencia, Madrid–Alicante, Madrid–Seville and Madrid–Málaga. As a result, both service supply and passenger demand increased.

On the main corridors, frequency rose from 78 to 115 daily services, and seat capacity increased by 60% (from almost 24 million in 2019 to around 37 million in 2023). In terms of demand, this increased by up to 45% (from around 20 million passengers in 2019 to more than 30 million in 2023).

These strong results from liberalisation increased the market share of high-speed rail to above 80% on most corridors where both modes compete. Airlines responded to this increased competition by reducing seat capacity, replacing some aircraft models with smaller ones. However, flight frequency remained unchanged.

Neither the market nor regulation reduces flights

“The major expansion of high-speed rail in Spain due to liberalisation has not led to a reduction in the number of flights,” the three authors of the article state: Daniel Albalate, Director of the Public Policy Analysis and Evaluation Observatory at the UB; Albert Gragera, from the UAB; and Professor Pere Suau-Sanchez, head of the Sustainability, Management and Transport Research Group (SUMAT) — part of the UOC-DIGIT centre — and lecturer in the Faculty of Economics and Business.

They add: “This has implications for promoting high-speed rail as a more sustainable mode of transport; making high-speed rail more attractive through market mechanisms does not appear to be a path that leads to significant environmental and climate improvements.”

“The reason appears to be the interest of network airlines, which must maintain high flight frequencies even with smaller aircraft, as many domestic flights feed into the Madrid–Barajas hub; even with fewer passengers, these flights continue to operate in order to fill intercontinental aircraft,” they explain.

“In conclusion, if a successful market liberalisation such as that of high-speed rail has not been able to reduce flights, it is unlikely that any market-driven dynamic will achieve this,” they state. They even argue that “even if Spanish legislation were to move towards banning short-haul flights, its impact on the number of flights and emissions would be very limited if flights connecting with hubs continue to be exempted.”

Reference article
Albalate, D. [Daniel], Gragera, A. [Albert] & Suau-Sanchez, P. [Pere] (2026). Fewer seats, resilient frequencies: Impacts of large-scale high-speed rail liberalisation on air transport supply, Research in Transportation Business & Management, 67. https://doi.org/10.1016/j.rtbm.2026.101712.

This study is related to the UOC research mission “Digital Transition and Sustainability” and to UN Sustainable Development Goal (SDG) 9, Industry, Innovation and Infrastructure.

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