Itineraries flown on 20+ days in the Jun 6 – Jul 31, 2026 schedule · each leg’s record Aug 2025 – Jul 2026

No clear winner: airlines and hours on this route all land within a few points of 78% on time.

Nonstops


Delta	DTW	SDF	1h 26m	78%	1.2%	1,301	Flying now
Spirit	DTW	SDF	–	100%few flights	0.0%	10	Not flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Louisville on time. Total trip = scheduled departure to arrival, layover included. Layovers up to 4 hours. Pick a connection for the details.


American Details →	DTW 05:37 → DFW 07:32AA 1108	1h 59m Dallas-Fort Worth	DFW 09:31 → SDF 12:48AA 3791 · flown by Envoy	7h 11m	96%	88%
Southwest Details →	DTW 05:50 → BWI 07:20WN 4534	3h 25m Baltimore	BWI 10:45 → SDF 12:30WN 1297	6h 40m	100%	88%
Delta Details →	DTW 05:17 → ATL 07:10DL 2375	3h 20m Atlanta	ATL 10:30 → SDF 11:53DL 1481	6h 36m	99%	84%
Southwest Details →	DTW 08:40 → MDW 08:55WN 1781	3h 50m Chicago	MDW 12:45 → SDF 14:55WN 4473	6h 15m	100%	83%
Delta Details →	DTW 12:25 → ATL 14:23DL 2188	3h 36m Atlanta	ATL 17:59 → SDF 19:24DL 2831	6h 59m	98%	82%
Southwest Details →	DTW 06:30 → BNA 07:05WN 4581	3h 00m Nashville	BNA 10:05 → SDF 12:00WN 670	5h 30m	98%	82%
Delta Details →	DTW 07:00 → LGA 08:47DL 1487	2h 18m New York	LGA 11:05 → SDF 13:32DL 5637 · flown by Republic	6h 32m	99%	81%
United Details →	DTW 06:00 → EWR 07:45UA 3652 · flown by Republic	2h 20m Newark	EWR 10:05 → SDF 12:21UA 3421 · flown by Republic	6h 21m	97%	81%
Tight connection: often missed
Delta Details →	DTW 19:35 → ATL 21:44DL 2045	1h 18m Atlanta	ATL 23:02 → SDF 00:26 +1DL 2624	4h 53m	73%	61%
United Details →	DTW 15:15 → EWR 17:10UA 3611 · flown by Republic	50m Newark	EWR 18:00 → SDF 20:25UA 3415 · flown by Republic	5h 10m	69%	51%

Same layover, different day-part

How often the first flight arrives too late to connect (45 min minimum), for one-ticket layovers of 45–80 minutes.

Morning

IAD · 58m · leaves 10:13 9%

ATL · 1h 04m · leaves 07:25 10%

MSP · 1h 05m · leaves 07:01 13%

Afternoon and evening

CLT · 1h 07m · leaves 19:58 24%

ATL · 54m · leaves 14:57 25%

EWR · 50m · leaves 15:15 31%

Delays build through the day, so an afternoon first leg eats the layover. A short connection is fine early in the morning and a gamble later on.

Mixing airlines

One ticketMiss it and the airline rebooks you; bags go through. 45 min is enough.

Separate ticketsMiss it and you buy a new ticket. Re-check bags, clear security again: we require 90 min.


Delta DL 4684 DTW 08:50 → MDW Southwest WN 4473 MDW 12:45 → SDF Connection details →	3h 31m	6h 05m	100%	85%
Delta DL 2331 DTW 10:10 → PHL American AA 4720 PHL 15:34 → SDF Connection details →	3h 48m	7h 35m	99%	83%
Delta DL 2341 DTW 07:10 → BWI Southwest WN 1297 BWI 10:45 → SDF Connection details →	2h 01m	5h 20m	95%	82%

Rank all connections, any airlines →

Regional partners count as the airline that sells them: SkyWest flying Delta Connection is one Delta ticket.

How these are worked out. Makes the connection: share of the last year’s flights where the first flight arrived with at least 45 minutes to spare (90 on separate tickets). Arrives on time: first flight not cancelled × connection made × second flight not cancelled and arriving within 15 minutes. Not yet counted: the second flight also leaving late (which helps), gate-to-gate distance at the hub, and rebooking after a missed connection.

About this data: US DOT on-time records, Aug 2025 – Jul 2026, all US airlines; regional flights count under the airline that sells them. Schedules (which flights and connections exist, and their times) are as of Jun 6 – Jul 31, 2026; seasonal flights outside that window aren’t ranked. Rebuilt monthly. JSON