Some days, I like to sit around and dream up the kind of data I can pull from Cirium. I’m only slightly ashamed to admit that this past weekend I had one of those days. A reader asked the question about how some airports have evolved over time with Southwest and the ultra low cost carriers (ULCCs), and I just kept going deeper and deeper down that rabbit hole until I realized I had spent far too much time on this and should be spending my weekends doing other things.
The look at an individual airport is very interesting, but I decided to start with something more high level. So, I pulled schedules for the full year 2015 and compared them to what’s now filed for the full year 2022. For ULCCs, I looked at Allegiant, Frontier, Spirit, and Sun Country since those are by far the biggest in the US. I then looked at all routes that had at least 10 departures in a year, and I plotted them using Great Circle Mapper.
Let’s take a trip down memory lane and look at how overlap has changed between the ULCCs and the big four airlines. Keep in mind that I’m not looking at actual capacity or revenue overlap — we do look at some of that in Cranky Network Weekly — but in this case I’m just looking at the routes that overlap then vs. now. And an important caveat… I am looking at complete airport overlap and not city overlap. So if Southwest flies something from Midway and Spirit from O’Hare, that does not count.
Let’s start with United.
United vs the ULCCs
I started with United, because these maps saw the least change. I’d say that’s because United’s hubs have seen some of the more significant overlap for the longest period of time, but it’s more than that. In 2015, United had 13.7 percent of its routes overlap with ULCCs. That had risen only to 16.5 percent by 2022, an increase of 2.8 points.
Most notably, of course, is Denver where Frontier has held court for years prior to 2015. Despite that, Denver did see serious inroads made by the ULCCs. There was overlap on 34 percent of United’s Denver routes in 2015 but that surged to 41 percent in 2022. The other big gainer was in Newark where there was no overlap at all in 2015, but by 2022 with Spirit, Frontier, and Allegiant all angling for space, that had risen to 13 percent of routes.
What’s most interesting, however, is that in United’s other hubs, this was offset significantly. O’Hare actually saw its overlap drop from 17 percent to 10 percent, and Dulles from 9 percent to 3 percent. At Dulles, it has likely been a result of the ULCCs failing to make it work whereas at O’Hare it’s more about United’s growing presence into new markets that don’t have that competition.
The rest of the hubs saw more minor change, and United has always been the weakest of the big three in Florida where the biggest growth has been for the ULCCs. So in that sense, United is lucky.
American vs the ULCCs
This one was a surprise to me. I had expected American’s overlap to grow significantly considering the entry of ULCCs into Miami and the growth of American in Austin, but the increase in overlap between 2015 to 2022 was only 5.6 points… from 9.4 percent to 15 percent.
So what happened with American? Well, Philly happened. Philly became a big operation for Frontier, and overlap jumped from 13 percent to 28 percent. And of course, Miami happened. With everyone racing into Miami, overlap went from a mere 6 percent all the way to 26 percent, including significant flying into Latin America. LAX also saw growth from 8 percent to 37 percent, but those are smaller numbers for American anyway.
The rest of the markets didn’t change much. Chicago’s percentage actually went down as American added many new routes that it didn’t operate, most of which do not have ULCC competition. And DFW dropped a bit as well, probably because Spirit was in there early and then focused growth elsewhere during this time period. That appears ready to change as several airlines have turned their eyes toward DFW this summer.
Delta vs the ULCCs
Of all the airlines, Delta held the biggest surprise. It went from having 12 percent of routes overlap all the way up to 19.3 percent, a gain of 7.2 points and the highest increase of the big three. I did not expect to see that much of a change.
I was taken aback when I saw what had happened in Minneapolis/St Paul. Delta and Sun Country have co-existed for years, but in 2015 the overlap was only 28 percent. By 2022 it had climbed to 44 percent. Some of this is the relentless march of Sun Country into additional markets as it gets more airplanes, but some of this is also a Delta retreat. I was puzzled when I looked at the map and saw a decrease in overlapping Mexico flying from 2015 to 2022. That’s not because Sun Country stopped it. It’s because Delta did.
The other big change was at home base in Atlanta. Overlap rose from 9.8 percent to 17. 8 percent, a near doubling. This is happening as both Frontier and Spirit build up the airport more and establish crew bases. More overlap is coming.
Other than that, the rest of Delta’s hubs were fairly steady. Yes, Detroit increased from 13.5 percent to 17.4 percent, so that is notable, but everything else changed less than two percent.
Southwest vs the ULCCs
No airline has seen a more significant change in overlap with the ULCCs than Southwest. In 2015, it had 14.4 percent of routes overlapping, but by 2022 it had spiked all the way to 35.6 percent. The maps above couldn’t look more different.
There’s a lot going on in here to explain why the overlap has increased so much. First, we have to remember that over the last couple of years, Southwest has gone into more than a dozen new airports, including some like Miami, Houston/Intercontinental, and Chicago/O’Hare that have a significant ULCC presence. So this is partially because of Southwest expanding, but Southwest also doesn’t fly into the smallest airports that the big three serve. Those small airports shield the legacies from a higher percentage of overlap since the ULCCs don’t serve those, at least not to airline hubs. Southwest doesn’t have that protection.
Let’s also not overlook the fact that Southwest has a large presence in heavy leisure markets where the ULCCs have done their best work: Florida and Las Vegas. Las Vegas is a long-time Southwest stronghold, but its overlap has gone from 45 percent of routes in 2015 to 80 percent today. In Orlando, the jump was from 22 to 86 percent and Fort Lauderdale from 33 to 71 percent. Those numbers are staggering.
At the same time, we’ve seen ULCCs move into the old abandoned midwestern hubs in spades. In 2015, Southwest flew to 13 places from Pittsburgh with no ULCC overlap. This year it’s 16 airports but 10 of them have ULCC competition.
With that backdrop, it is no surprise to see the overall ULCC overlap with Southwest jump up so much.
We know the ULCCs are growing, and they will continue to do so with all the airplanes they have on order. They started with the most obvious leisure destinations, but they have rapidly expanded. Airlines with facility constraints at their legacy hubs have succeeded at keeping them out for the most part, but even in those places, the ULCCs have continued to find a way.
We’ve already seen it in Europe where the ULCCs have connected nearly any two points you can imagine as the legacies have concentrated their efforts in their hubs. Southwest is a unique difference between Europe and the US since that type of hybrid doesn’t exist over there. But even that won’t stop the ULCCs from continuing to grow their footprints.