I was asked a deceptively simple question on Twitter: why would people bother with taking a train when flying is available? In my (admittedly primitive) modeling for high-speed rail ridership in the US, I’m including some nontrivial ridership and revenue coming from cities at a distance that people do fly, like Boston-Washington, New York-Cleveland, and so on. What gives?
The simplest answer is that evidently people do take trains at such distances. Statista has some examples, all with more rail than air travel; an Air2Rail paper by Arie Bleijenberg has some numbers within Europe in Annex B. The main factor is rail travel time, with a malus for markets with poor rail connectivity (such as anything crossing the Channel). When trains take four hours, as on Paris-Toulon, they have a small majority of the travel market (source, p. 14 – look at the 2009 numbers, the 2023 numbers being a speculation); Paris-Nice manages to have respectable modal split even at 5.5 hours.
But that answer is frustrating. Why do people take trains for 4-5 hours when it’s possible to fly in an hour?
The first answer is door-to-door travel time. This includes all of the following features:
- Airports are far from city centers whereas train stations are almost universally within them; even taking into account that most people don’t live in city center, they tend to have easier access to the train station than to the airport, and then destinations are massively centralized in the city.
- Trains have no security theater to delay passengers, and passengers can get from the station entrance to the platform in 10 minutes if the station is exceptionally labyrinthine and they’re unfamiliar with its layout and two minutes if it’s not or they are.
- Passengers with luggage can take it on the train and don’t have to be further delayed for baggage claim.
All of these features work to make trains more pleasant than planes even when the door-to-door trip times are equal. The sequential queuing for security and then boarding on a plane is a hassle in addition to extra time; of note, in the Air2Rail link, the most glaring underperformance in high-speed rail modal split relative to trip times is for routes crossing the Channel, because they have such queuing courtesy of British paranoia about terrorism in the Chunnel and also charge higher fares.
The advantages of planes over trains are elsewhere. First, planes are faster airport-to-airport than trains are station-to-station, and as a result, a longer distances they are much faster door-to-door and therefore dominant. And second, trains travel in lines whereas planes travel point-to-point; it’s not hard to come up with city pairs that have no reason to have an even semi-direct high-speed railway between them even though they are at rail-appropriate range, for example Nice-Geneva (290 km) or Cincinnati-Charlotte (540 km).
But once the lines exist, they should get substantial passenger traffic – and the modal split with air is very well-documented in the literature and the overall traffic is still fairly well-modeled as well.