Consider that the air route between Madrid and Barcelona, two cities that are about 620 km (~385 miles) apart, used to be the busiest air traffic route in the W

Consider that the air route between Madrid and Barcelona, two cities that are about 620 km (~385 miles) apart, used to be the busiest air traffic route in the World by frequency of flights until 2007. And that was the case even though these cities were already well connected by motorways as well as by conventional train services. Now, since the high-speed rail link opened in 2008, the Madrid-Barcelona air route doesn't even make the top 20 of busiest routes worldwide. That is the case even though the flight is less than 1h 30m, both cities' airports are well connected to and close to the city centres, and high-speed train tickets have always been more expensive than flying on average. The killer feature of the high-speed train, particularly for business users, is to be able to get from one city centre to the other in at most 3h 20m —if it is a stopping train— or 2h 30m —if it is direct. No need to travel to and from each airport, or deal with airport security, queues, delays, etc. No need to disconnect your phone during the trip. No need to switch off laptops on departure or arrival. And this example is for only two cities which are farther apart than each of Houston, Dallas, or San Antonio are from each other. Imagine if it were possible to get between each of their downtowns in 1h 30m or 2h at most, or from downtown Austin to downtown San Antonio in 30m. The synergistic effects on the economy are hard to predict, but they would be huge.