Only 29% Full: Delta Air Lines' 10 Emptiest Routes Revealed

James lives and breathes route development. Educated in Air Transport Management at Loughborough University and Cranfield University, James has a PhD in airline strategy. James was Market Opportunity Analyst at London Luton Airport and Chief Analyst at anna.aero. He taught airline strategy and economics to undergraduate and postgraduate students for five years and has worked closely with multiple carriers on route and market intelligence projects. He is based near London, UK. Delta Air Lines was the second-largest airline serving the US last year. According to the country's Department of Transportation, the SkyTeam member carried 201 million passengers, which was equivalent to 551,000 people daily. The airline transported 18.2% of the country's total traffic. Its share rose to over a fifth for the vast domestic market, which was less than two percentage points lower than for American Airlines, which ranked first. But Delta only had 11.3% of the US's international traffic, which was the lowest proportion of the so-called Big Three operators. Delta's Ten Routes With The Lowest Load Factors Across all of 2025, the DOT indicates that Delta's average seat load factor across its entire network was 83.7%. This was marginally higher than for United Airlines. When only Delta's domestic routes are considered, its result was 83.2%. In contrast, it achieved 84.8% internationally. As always with such analysis, load factors should not be considered in isolation. It is important to remember that it is always about how it was achieved. Of course, if they're particularly low, as in the following bottom-ten results, that speaks volumes. Without additional context, it'd be misleading. After all, nearly all of them are funded by the Essential Air Service, without which they'd not be served. Virtually all of United's entries were funded too. Only one of Delta's ten routes has ended, and that was not subsidized. It was realiant on normal commercial realities. Seat Load Factor In Full Year 2025* Route** Round-Trip Traffic*** 29.3% Minneapolis-Watertown (funded by the EAS) 4,452 35.8% Minneapolis-Hibbing (funded by the EAS) 22,442 37.4% Salt Lake City-Cedar City (funded by the EAS) 23,400 41.3% Austin-Harlingen (this route has now ended) 9,226 41.4% Minneapolis-Escanaba (funded by the EAS) 10,692 41.6% Detroit-Alpena (funded by the EAS) 25,097 43.5% New York LaGuardia-Worcester 17,779 44.1% Minneapolis-International Falls (funded by the EAS) 28,787 47.6% Washington Reagan-Lexington 19,544 48.2% Minneapolis-Brainerd (funded by the EAS) 30,668 * According to the US DOT. Based on a minimum of 2,500 passengers ** According to the US DOT *** According to the US DOT A Look At Delta Between Austin & Harlingen Everyone knows that Delta is growing quickly in Austin. It is a key city for development. In 2025, DOT data indicates that it carried 3.7 million passengers to/from the Texas capital, which was its record year to date. Traffic smashed its prior record, held in 2024, by 13%. It was Austin's second-largest operator, after Southwest. The growth has not let up. Compared to 2025, Delta's schedule submission to Cirium indicates that it has added 15% more seats for sale in 2026. This partly explains why close partner Korean Air 'might' be considering operating between Seoul and Austin. In 2025, Delta had 27+ routes from Austin. At just 237 nautical miles (439 km) each way, they included its shortest route: Harlingen. Flights on this intrastate operation existed between October 2024 and June 2025, with SkyWest E175s exclusively deployed. The DOT data shows that 54% of passengers connected in Austin, while 46% were local. Related Massive Boost: Singapore Airlines Adds Airbus A380 Flights On This Critical Long-Haul Route Superjumbo service returns to this hugely important route after a three-year absence. Posts By James Pearson What About LaGuardia To Worcester? It would be very easy to dismiss this market, which covers just 127 nautical miles (235 km) each way, as a slot-sitting exercise. And to some degree it is. However, flights have operated since August 2019 -- nearly seven years. That's an awfully long time for such an endeavor. In 2025, Delta served the market daily except on Saturdays, entirely on Endeavor Air CRJ900s. The schedule saw flights leave LaGuardia in the early afternoon and depart from Worcester in the late afternoon. The timings did not help with loads. Given that Delta Connection nearly always flew the 70-seat CRJ900, which was due to the scope clause requirement. With a load of 43.5%, it only filled an average of 30 seats per departure. Ouch. And of these, just under half of the passengers were local. Given the obviously poor performance -- especially after seven years -- the role of slot-sitting must not be dismissed. Quiz 5 Questions Delta's Load Factor Lows: Quiz on Efficiency and Routes Your Top Score -- Attempts -- Start Quiz 0 0 Report Error Found an error? Send it info@simpleflying.com so it can be corrected.