U.S. Sen. Robert Casey (D., Pa.) has urged the chief executive officer of US Airways Group Inc. to rescind the airline’s fare hike planned for flights between Philadelphia and Pittsburgh in early January, when only US Airways will fly between the two cities.

The Pittsburgh Post-Gazette reported Tuesday that when Southwest Airlines Co. drops its flights between Philadelphia and Pittsburgh on Jan. 8, the price for a US Airways round-trip ticket will jump from $118 plus tax, to $698 plus tax.

Now one might argue that this is an unusual situation, with a single carrier monopolizing a route. Several carriers fly SF-LA. And yet the underlying factors suggest that the SF-LA route won’t see cheap flights forever – and global evidence shows riders will switch to trains anyway if given the option.

In 2008, Southwest’s founder Herb Kelleher suggested that rising fuel prices would eventually force airlines to cut flights:

Herb Kelleher, the iconic co-founder of Southwest Airlines who stepped down as chairman Wednesday, said flying could become something that only business travelers or the affluent can afford, much as it was in the 1950s and ’60s.

“You may see a lot less air service across the United States, and that’s really a shame,” Kelleher said. “We are heading back in that direction.”

The fuel price spike in 2008 led many airlines to cut service serving California airports – Delta reduced its flights from LAX by 13%. The experience taught many airlines that short-haul flights are not necessarily a basis on which to build a profitable airline.

In 2010 JetBlue execs argued that short-haul routes aren’t all that great. From JetBlue CEO Dave Barger:

Q: Do you see nationwide high-speed rail as a threat or complement to the airline industry?

A: It’s a complement. I don’t think we need hundreds of departures every day from the Bay Area to Los Angeles.

And JetBlue COO Rob Maruster:

It was an event filled with charts and maps that drove home how overwhelmed and outdated current air traffic control technology is. One solution [JetBlue COO Rob] Maruster said was obvious is taking airline passengers off some routes, like New York to Boston. “It seems like there’s a mode that might work better for us in that regard. When we see things like high-speed rail going into South Florida, we say OK, that makes sense. But I think this region, with almost 25 million people in the Tri-State area, makes a lot more sense for those kind of things.” Maruster says he’d like to see New York City and federal transportation officials put out a 20 or 30-year vision that addresses how airplanes, trains and other modes of transportation can be put together. He hasn’t seen one yet.

The writing is on the wall. Airlines don’t see a long-term future in short-haul flights. Medium and long-distance routes are where their profits will come from in the future. As fuel prices rise, the short-haul trips will either become too expensive for most people to afford, or too infrequent to be useful.

Of course, we also know that when HSR is offered as an option, it competes very well against short-haul airline routes. In Spain the world’s busiest air corridor, the Madrid-Barcelona route, lost over half its ridership to the AVE high speed train within 2 years of the AVE to Barcelona going online. The Acela carries more than half of the air-rail market on the NEC.

So while folks stuck in the 20th century who refuse to admit the need to change may crow endlessly about cheap Southwest fares between SF and LA, the reality is clear: the era of cheap flights is ending, and in any case people will choose high speed trains anyway.

Trips like these always remind me of how much easier HSR would be. To get here, my wife took me to San Jose Airport yesterday, where I took a flight to LAX. Flights from Monterey to LAX were insanely expensive by the time I booked my flight just over a week ago, and I couldn’t find any affordable flights that met my schedule needs from San Jose to John Wayne Airport. So I flew into LAX and then hopped on board the FlyAway Bus to Irvine, where my family picked me up and drove me back to Tustin. Door to door, it was 6 hours:

Left Monterey at 7 AM, arrived at SJC at 8:15
Plane boarded at 9:15, took off at 9:45
Landed at LAX at 11
Boarded FlyAway bus at 11:45
Arrived at Irvine around 12:40
Arrived in Tustin around 1 PM

Sure, there was some waiting around at LAX for the FlyAway bus, and perhaps I could have left Monterey around 7:30. But even if I had left Monterey then, and had caught the FlyAway bus as soon as I made it out of the terminal (which took a good 15 minutes since I flew into the commuter terminal) I’d have saved 45 minutes or so. So 5-6 hours is the ballpark.

Now how long would that take on HSR? According to the CHSRA, Gilroy to Anaheim will be 2 hours, 16 minutes. Of course, depending on the mix of local stops, it might take longer. Still, it’s 45 minutes from Monterey to Gilroy, so let’s say I leave Monterey 60 minutes before departure (since I’d want to leave some time to spare). Then spend maybe 2:30 on the train, and 20 minutes or so from ARTIC to Tustin, depending on which family member picks me up. That’s about 4 hours’ travel time. Much better than 6, even if fares were set at 83% of comparable airfares. And even if I needed to pad my trip a bit more between Monterey and Gilroy, it’s still a savings over air travel, if not quite as dramatic, and likely for a cheaper price, especially once you factor in the increases in oil prices over the next 10 years.

Every time I travel back to Southern California, I always think “this would be so much easier on high speed rail.”