Why Trains Will Struggle to Replace Short Flights

Poor rail links to hub airports are a headache for those who see trains as a broad alternative to single-aisle planes

By Jon Sindreu of The WSJ. Excerpts:

"a new paper by Vreni Reiter, Augusto Voltes-Dorta and Pere Suau-Sánchez casts doubt over the extent to which trains can take over.

The authors use Germany as an example of a dense, distributed population with extensive access to high-speed rail. They identified 87 nonstop flight routes—about 32% of Germany’s annual seat capacity—that would be theoretical targets of a ban, with the longest train journey taking five hours and 37 minutes. 

Crucially, they account for something that most studies of this kind don’t: About a quarter of passengers aren’t traveling point to point, but rather going to a hub airport and then hopping on a long-haul plane.

As is the case with Air France, officials would presumably be more tolerant of such flights. But that would also limit the environmental benefits: In a scenario in which airlines would only be required to use 10% of seats for connections to preserve a route, air-travel carbon emissions would only fall 2.7%.

Increasing the threshold to 80% would yield a larger 22% cut, but 71% of passengers would be diverted to rail or direct long-haul flights which, on average, would make journeys two hours longer. In some extreme cases of popular routes involving non-hub airports, such as Berlin-Stuttgart, even a 10% threshold would leave more than a million people each year with no alternative but to more than double their travel time.

The lessons are applicable everywhere. High-speed rail will keep increasing its market share in short routes with a lot of point-to-point demand, such as Munich-Berlin, Barcelona-Madrid or Seoul-Busan. But to act as hub feeders, rail networks would need a massive upgrade.

Capacity must be sized to the few departure hours in which airlines fill their big planes, leaving wasted space for much of the day. Trains must also take people directly to airports, not city centers. Such “intermodal” networks are often nonexistent. Spain, for example, is only surpassed by China in kilometers of high-speed rail, but so far hasn’t connected its main airports to it. The investments needed to deliver all of this high-speed capacity to smaller cities aren’t just hugely costly, but also polluting.

“A cost-benefit analysis leaves blanket-ban policies in a bad place,” said Dr. Suau-Sánchez. “A surgical approach is best.”"