The Fall of the St. Louis Hub
STL → Chicago (ORD + MDW) carried 102,973 June passengers in 1999; by 2025 it was down to 47,474, tracing STL's shift from hub connector to local O&D market.
The Question
What happens to a corridor when a city loses its hub? St. Louis was TWA’s fortress hub in the 1990s, then shifted into a local O&D market after the American-TWA integration and long de-hubbing cycle.
For Chicago, you need both airports to see the full picture. STL-ORD alone misses Midway’s Southwest-heavy flow that dominated the corridor in the 1990s. This page treats Chicago as ORD + MDW and tracks how carrier mix, frequency, and fares changed over time.
Building a Multi-Dataset View
This analysis combines three AirStream datasets:
- Performance data (2002-2025): monthly flight counts and reliability metrics by carrier
- T-100 traffic data (1993-2025): June passenger snapshots every 3 years
- DB1B ticket data (2003-2025): quarterly fare and revenue by operating carrier
Each chart uses destination=ORD,MDW for the same periods to represent the full Chicago corridor.
Monthly Flight Volume: Chicago Corridor Frequency
The performance/breakdown endpoint supports up to 12 months per request. To cover January 2002 through December 2025, we stitch 24 annual windows, running each window once with destination=ORD,MDW, then summing by month and carrier.
- Chunk pattern:
- 24 windows of 12 months each (Jan–Dec per year, 2002 through 2025)
- Examples:
- 2002-01→2002-12 · 2014-01→2014-12 · 2025-01→2025-12
Run all windows once with destination=ORD,MDW, then aggregate the monthly results.
Monthly Flights on STL → Chicago (ORD + MDW) — 2002 to 2025
By reporting carrier · Performance dataset · ORD and MDW combined
/performance/breakdown?by=carrier&origin=STL&destination=ORD,MDW · Stitched across 24 annual query windowsWhat the data shows: In January 2002, STL → Chicago had 886 flights (WN 399, AA 301, UA 186). The monthly peak was March 2003 at 948 flights. By June 2009, frequency was down to 568 flights; by 2024, it averaged 375 flights per month.
Passenger Volume: Three Decades Across Two Chicago Airports
To include the full 1990s pattern, we use T-100 traffic/segments/breakdown snapshots for June every three years with destination=ORD,MDW.
- Snapshot years:
- 1993, 1996, 1999, 2002, 2005, 2008, 2011, 2014, 2017, 2020, 2023, 2025
- Month:
- June (peak summer scheduling)
T-100 is a full census. For this corridor, use destination=ORD,MDW to represent Chicago city-pair demand.
STL → Chicago Passenger Snapshots by Carrier (ORD + MDW) — 1993 to 2025
June of each snapshot year · T-100 scheduled service · Stacked by operating carrier
/traffic/segments/breakdown?by=carrier&origin=STL&destination=ORD,MDW&service_class=FThe carrier story has three phases:
Act 1 — Dual-airport 1990s (1993-1999): June 1993 carried 85,072 passengers across Chicago airports, led by Southwest at Midway (35,090) with United, American, and TWA all sizable. By June 1999, total corridor traffic peaked at 102,973 passengers (WN 41,018; TW 36,541).
Act 2 — Post-merger transition (2002-2014): June 2002 dropped to 50,294 passengers, then rebounded to 86,490 by 2008 before declining again. American led much of the mid-2000s at ORD while Southwest remained the corridor anchor through MDW.
Act 3 — Fragmented modern mix (2017-2025): June 2025 reached 47,474 passengers, split across Southwest, United, American, and multiple regional operators (GoJet, SkyWest, Envoy, Republic).
STL’s Broader Decline: Top Destinations Over Time
The Chicago corridor trend sits inside STL’s larger contraction. Using T-100 by destination, we can track the top STL routes over the same snapshots.
- Snapshot years:
- 1993, 1996, 1999, 2002, 2005, 2008, 2011, 2014, 2017, 2020, 2023, 2025
- Scope:
- Domestic (region=D), top 30 destinations per snapshot
This view measures STL-wide domestic demand and route mix changes, not just Chicago.
STL Domestic Top Destinations Over Time
T-100 snapshots (June) · top 10 destinations per year
/traffic/segments/breakdown?by=destination&origin=STL&service_class=F®ion=D (snapshots)In June 1993, STL served 96 domestic destinations with nearly 963,000 passengers. In June 1999, STL hit almost 1.5 million domestic passengers. By June 2025, domestic volume was roughly 683,000, less than half the 1999 level.
Chicago’s airport split matters here too: in 1993, Midway (MDW) was STL’s top destination while ORD ranked fourth. Combined, Chicago clearly led the market even when ORD alone did not.
Fare Economics: What Passengers Pay
For fares, we use DB1B tickets/markets/breakdown and stitch nine quarterly windows (10 quarters max per call). As above, each window uses destination=ORD,MDW and is then aggregated.
- Chunk 1:
- start_year=2003&start_quarter=1&end_year=2005&end_quarter=2
- Chunk 2:
- start_year=2005&start_quarter=3&end_year=2007&end_quarter=4
- Chunk 3:
- start_year=2008&start_quarter=1&end_year=2010&end_quarter=2
- Chunk 4:
- start_year=2010&start_quarter=3&end_year=2012&end_quarter=4
- Chunk 5:
- start_year=2013&start_quarter=1&end_year=2015&end_quarter=2
- Chunk 6:
- start_year=2015&start_quarter=3&end_year=2017&end_quarter=4
- Chunk 7:
- start_year=2018&start_quarter=1&end_year=2020&end_quarter=2
- Chunk 8:
- start_year=2020&start_quarter=3&end_year=2022&end_quarter=4
- Chunk 9:
- start_year=2023&start_quarter=1&end_year=2025&end_quarter=2
DB1B is a 10% sample. Use destination=ORD,MDW, exclude carrier code 99, then aggregate passengers and revenue.
STL → Chicago (ORD + MDW) Average Fare & Passengers — 2003 to 2025
Quarterly · DB1B ticket data · All operating carriers
/tickets/markets/breakdown?by=opcarrier&origin=STL&destination=ORD,MDW · Stitched across 9 query windowsWhat the data shows: In 2003-Q1, STL → Chicago average fare was $83.71 with 7,531 sampled passengers. Passenger volume peaked at 9,387 in 2004-Q2. By 2025-Q2, average fare reached $198.19 while sampled passengers fell to 4,050.
What the Data Tells Us
Treating Chicago as ORD + MDW changes the interpretation:
- 1990s structure was dual-airport, not ORD-only: Midway traffic (mainly Southwest) carried a large share of corridor demand while TWA and other legacy carriers remained important at ORD.
- Post-2001 shock was real but uneven: corridor demand dropped sharply after the merger/9-11 period, then partially recovered before resuming decline.
- De-hubbing still dominates the long run: STL lost the hub-era traffic premium, and corridor frequency contracted materially over two decades.
- Current market is broad but thinner: no single legacy carrier controls the route; Southwest plus multiple regional operators now define the corridor.
Every chart on this page is reproducible from the endpoint patterns shown above using destination=ORD,MDW.