Beyond long lines and TSA pat-downs, a major headache for passengers at many U.S. airports is spotty cell phone service. Now, a new report from mobile industry research firm RootMetrics aims to quantify that headache.

Wireless operators face a number of challenges in beaming their signals to airports. For one thing, airports often span vast areas, and cell phone towers can't be built on their property. Couple that with thick building materials, large crowds and underground construction and you've got a recipe for poor service.

The report measures data speeds for the four major U.S. carriers -- AT&T (T), Verizon (VZ), T-Mobile (TMUS) and Sprint (S) -- at the country's 50 busiest airports.

Verizon was the clear winner, taking top honors at 30 of the 50 airports. Verizon also had the fastest median download speed at a single airport: a swift 77.8 megabits per second at Atlanta's Hartsfield-Jackson International Airport.

T-Mobile leapfrogged AT&T for second, while Sprint brought up the rear.

In ranking the airports, RootMetrics also took into account other factors like call performance, text performance, upload speeds and network reliability in addition to download speed. Here's the full list of the best-performing airports along with the median download speeds for each of the four carriers:

Related: The 5 best -- and worst -- airports for cell phone service

1.) Fort Myers, FL (RSW) -- Southwest Florida International Airport

Verizon: 38.5 Mbps, Sprint: 13.0, AT&T: 9.7, T-Mobile: 8.6

2.) Chicago, IL (ORD) -- Chicago O'Hare International Airport

Verizon: 55.6, Sprint: 30.4, AT&T: 8.2, T-Mobile: 7.0

3.) Orange County, CA (SNA) -- John Wayne Airport

Verizon: 22.4, T-Mobile: 18.5, Sprint: 15.2, AT&T: 7.1

4.) Memphis, TN (MEM) -- Memphis International Airport

T-Mobile: 16.7, AT&T: 14.4, Verizon: 14.1, Sprint: 2.4

5.) Milwaukee, WI (MKE) -- General Mitchell International Airport

Verizon: 23.1, AT&T: 13.4, T-Mobile: 5.6, Sprint, 2.7

6.) Indianapolis, IN (IND) -- Indianapolis International Airport

AT&T: 30.6, Verizon, 24.5, T-Mobile: 3.2, Sprint: 2.1

7.) Washington, DC (DCA) -- Ronald Reagan Washington National Airport

T-Mobile: 16.2, AT&T: 14.4, Verizon: 6.5, Sprint: 0.8

8.) Las Vegas, NV (LAS) -- McCarran International Airport

Verizon: 21.5, AT&T: 17.0, T-Mobile: 6.9, Sprint: 1.6

9.) Columbus, OH (CMH) -- Port Columbus International Airport

Verizon: 25.7, T-Mobile: 22.7, Sprint: 5.6, AT&T: 3.8

10.) Pittsburgh, PA (PIT) Pittsburgh International Airport

Verizon: 14.7, AT&T: 12.4, T-Mobile: 10.1, Sprint: 4.0

Related: Can Sprint do anything but suck?

11.) Atlanta, GA (ATL) -- Hartsfield-Jackson Atlanta International Airport

Verizon: 77.8, AT&T: 33.9, T-Mobile: 27.3, Sprint: 0.4

12.) Chicago, IL (MDW) -- Chicago Midway International Airport

Verizon: 71.3, T-Mobile: 13.3, AT&T: 5.5, Sprint: 2.5

13.) Baltimore, MD (BWI) -- Baltimore/Washington International Thurgood Marshall Airport

Verizon: 43.0, AT&T: 12.7, Sprint: 3.4, T-Mobile: 3.2

14.) Raleigh, NC (RDU) -- Raleigh-Durham International Airport

Verizon: 20.2, AT&T: 11.0, T-Mobile: 5.4, Sprint: 2.7

15.) Miami, FL (FLL) -- Fort Lauderdale/Hollywood International Airport

Verizon: 15.5, Sprint: 10.6, AT&T: 4.8, T-Mobile: 4.3

16.) Sacramento, CA (SMF) -- Sacramento International Airport

T-Mobile: 23.5, AT&T: 17.5, Verizon: 13.7, Sprint: 0.3

17.) Seattle, WA (SEA) -- Seattle-Tacoma International Airport

T-Mobile: 15.0, Verizon: 11.1, AT&T: 8.0, Sprint: 1.6

18.) Washington, DC (IAD) -- Washington Dulles International Airport

AT&T: 14.7, Verizon: 13.5, T-Mobile: 4.2, Sprint: 2.7

19.) Kansas City, MO (MCI) -- Kansas City International Airport

T-Mobile: 13.5, Verizon: 10.2, AT&T: 9.5, Sprint: 1.1

20.) New York City (LGA) -- LaGuardia Airport

Verizon: 21.1, AT&T: 13.8, T-Mobile: 4.7, Sprint: 3.8

Related: FCC calls Verizon plan to throttle speeds 'disturbing'

21.) Cleveland, OH (CLE) -- Cleveland Hopkins International Airport

T-Mobile: 24.7, Verizon: 15.1, AT&T: 7.6, Sprint: 0.5

22.) Orlando, FL (MCO) -- Orlando International Airport

T-Mobile: 22.2, Verizon: 14.2, AT&T: 9.5, Sprint: 1.2

23.) Portland, OR (PDX) -- Portland International Airport

T-Mobile: 15.0, AT&T: 6.5, Sprint: 5.0, Verizon: 4.5

24.) Charlotte, NC (CLT) -- Charlotte Douglas International Airport

AT&T: 9.1, Verizon: 7.9, T-Mobile: 4.4, Sprint: 1.1

25.) Tampa, FL (TPA) -- Tampa International Airport

T-Mobile: 16.1, Sprint: 14.1, Verizon: 9.9, AT&T: 5.3

26.) Dallas, TX (DFW) -- Dallas/Fort Worth International Airport

T-Mobile: 14.8, Verizon: 10.3, AT&T: 10.0, Sprint: 0.6

27.) Boston, MA (BOS) -- General Edward Lawrence Logan International Airport

AT&T: 11.7, T-Mobile: 9.6, Verizon: 6.2, Sprint: 1.0

28.) San Jose, CA (SJC) -- Norman Y. Mineta San Jose International Airport

Verizon: 17.5, T-Mobile: 7.4, Sprint: 3.6, AT&T: 2.7

29.) Miami, FL (MIA) -- Miami International Airport

Verizon: 22.2, T-Mobile: 5.0. AT&T: 4.0, Sprint: 4.0

30.) Detroit, MI (DTW) -- Detroit Metropolitan Wayne County Airport

AT&T: 22.4, Verizon: 13.1, T-Mobile: 4.4, Sprint: 0.5

Related: Netflix and AT&T strike deal to boost streaming speeds

31.) Los Angeles, CA (LAX) -- Los Angeles International Airport

Verizon: 18.2, Sprint: 15.1, AT&T: 3.0, T-Mobile: 0.7

32.) Austin, TX (AUS) -- Austin-Bergstrom International Airport

AT&T: 29.0, Verizon: 28.5, T-Mobile: 5.1, Sprint: 0.5

33.) Salt Lake City, UT (SLC) -- Salt Lake City International Airport

Verizon: 15.8, AT&T: 4.0, Sprint: 3.2, T-Mobile: 2.8

34.) Honolulu, HI (HNL) -- Honolulu International Airport

Verizon: 15.0, T-Mobile: 10.9, AT&T: 5.1, Sprint: 0.5

35.) Houston, TX (HOU) -- William P. Hobby Airport

Verizon: 11.1, T-Mobile: 3.6, AT&T: 2.7, Sprint: 2.1

36.) Denver, CO (DEN) -- Denver International Airport

T-Mobile: 12.7, Verizon: 11.8, AT&T: 8.1, Sprint: 0.3

37.) Oakland, CA (OAK) -- Metropolitan Oakland International Airport

T-Mobile: 22.5, Verizon: 16.0, AT&T: 6.0, Sprint: 0.4

38.) Houston, TX (IAH) -- George Bush Intercontinental Airport

T-Mobile: 23.8, Verizon: 10.9, AT&T: 10.2, Sprint: 0.4

39.) Phoenix, AZ (PHX) -- Phoenix Sky Harbor International Airport

T-Mobile: 13.3, AT&T: 7.6, Verizon: 1.8, Sprint: 0.6

40.) Dallas, TX (DAL) -- Dallas Love Field

AT&T: 37.4, Verizon: 34.6, T-Mobile: 5.1, Sprint: 0.2

Related: Netflix partner says Verizon slows traffic

41.) New York, NY (JFK) -- John F. Kennedy International Airport

AT&T: 21.0, T-Mobile: 9.8, Verizon: 4.6, Sprint: 1.2

42.) San Francisco, CA (SFO) -- San Francisco International Airport

Verizon: 12.0, AT&T: 2.8, T-Mobile: 2.5, Sprint: 0.7

43.) San Antonio, TX (SAT) -- San Antonio International Airport

T-Mobile: 11.7, Verizon: 11.6, AT&T: 4.5, Sprint: 0.3

44.) St. Louis, MO (STL) -- Lambert-St. Louis International Airport

T-Mobile: 17.3, Sprint: 8.2, Verizon: 3.6, AT&T: 2.2

45.) Nashville, TN (BNA) -- Nashville International Airport

T-Mobile: 9.5, AT&T: 4.6, Sprint: 2.3, Verizon: 1.9

46.) New Orleans, LA (MSY) -- Louis Armstrong New Orleans International Airport

Verizon: 7.7, AT&T: 6.3, T-Mobile: 1.4, Sprint: 0.3

47.) Philadelphia, PA (PHL) -- Philadelphia International Airport

AT&T: 7.5, T-Mobile: 5.9, Verizon: 0.8, Sprint: 0.5

48.) Newark, NJ (EWR) -- Newark Liberty International Airport

T-Mobile: 13.4, Sprint: 9.6, AT&T, 9.3, Verizon: 4.5

49.) Minneapolis, MN (MSP) -- Minneapolis-St. Paul International Airport

T-Mobile: 16.7, AT&T: 10.0, Verizon: 1.4, Sprint: 0.3

50.) San Diego, CA (SAN) -- San Diego International Airport

Verizon: 3.2, AT&T: 2.7, T-Mobile: 2.6, Sprint: 0.3