High-speed rail is taking passengers away from domestic flights on Spain's main intercity corridors, but airlines are not cutting the number of services they operate, according to new research led by academics from the University of Barcelona, the Autonomous University of Barcelona and the Open University of Catalonia.

For travellers in Barcelona, especially people comparing air and rail on the Barcelona–Madrid corridor, the finding means more direct competition may show up in aircraft size and seat availability rather than in fewer daily departures. In practice, passengers may still see similar flight frequencies while finding fewer seats on sale from airlines.

The study was written by Daniel Albalate, director of the Observatory of Analysis and Evaluation of Public Policies at the University of Barcelona; Albert Gragera, professor in the Department of Applied Economics at the Autonomous University of Barcelona; and Pere Suau, head of the Sustainability, Management and Transport Research Group at the Open University of Catalonia's Research Centre on Digital Transformation and Governance.

High-speed rail significantly outperforms air travel in passenger numbers on major state corridors, but the number of flights on those same routes does not fall, even though the number of airline seats offered does decrease.

That is the main conclusion presented by the researchers in findings released by the Open University of Catalonia, known as UOC. The research was also reported by Diari ARA.

What the study says about rail and air competition

According to the researchers, high-speed rail has become the stronger mode in passenger numbers on major domestic corridors where trains and planes compete directly. Even so, airlines continue to operate flights on those routes instead of withdrawing frequencies at the same pace as passenger demand shifts to rail.

The distinction matters because frequency and capacity are not the same thing. An airline can keep a similar timetable while reducing the total number of seats by using smaller aircraft or adjusting cabin configurations.

  • The research focuses on major Spanish corridors where high-speed rail and air services overlap.
  • The central finding is that rail gains more passengers, while flight frequencies remain broadly in place.
  • The adjustment identified by the researchers is in airline seat supply, which falls even when the number of flights does not.

The UOC said the work was carried out by researchers from the three universities and examines how airlines respond when high-speed rail becomes a stronger competitor. The article does not suggest that air services disappear from the market. Instead, it points to a more limited airline response centred on capacity.

Why it matters for Barcelona passengers

For business commuters and other regular travellers choosing between Barcelona and Madrid, the research suggests that train competition may not automatically reduce the number of flights available from Barcelona airport. What may change first is the number of seats sold by airlines, which can affect fares, flexibility and availability on busy dates.

The wider pattern matches previous international research cited in the source material. An analysis by aviation data firm OAG of Eurostar's effect on London–Paris and London–Brussels found rail took substantial market share from airlines over time, while a survey article published in the peer-reviewed journal Transport Policy reviewed broader evidence on how high-speed rail affects airlines and airports.

No direct link to the full academic paper by the Barcelona researchers was provided in the verified source material. The publicly available account of the findings currently comes from the UOC's institutional release and Diari ARA's reporting.

Travellers comparing options on routes such as Barcelona–Madrid can check fares, journey times and seat availability directly through Renfe's AVE booking platform and the airlines serving the route before they travel.

Primary sources: Núria Quintana / Rubén Permuy, pmc.ncbi.nlm.nih.gov. Reported by Source Text Link, oag.com, lek.com, sciencedirect.com, ucits.org, alg-global.com, Xavier Grau del Cerro, techxplore.com, Mirage News, airlineratings.com, routesonline.com, researchgate.net, Diari ARA.