If the skies seem more crowded, it’s probably because they are. In 2018, we've seen passenger load factors hit an all-time high. With seat capacity hovering around 86% across all domestic flights, you're left with the feeling that every route is a busy one. While that assumption might not be far off, here is a definitive list of the busiest passenger routes and city-pairs in the United States.

America’s Most Popular Passenger Flights

Earlier this month, Routesonline released its annual list of the top 100 busiest routes on earth. Compiling data using OAG and Sabre, Routesonline combined passenger loads and the number of flights between two airport-to-airport routes to create their list of the world’s most in-demand commercial flight offerings.

Below I’ve listed the nation’s most popular passenger flights, how often they fly, and how many passengers were onboard these favored routes over the last year.

10. Atlanta (ATL) – Ft. Lauderdale (FLL)

Kicking off the top 10, we have this East Coast route that served 2,360,786 passengers across 15,858 flights last year. Mix in Delta’s mega hub in Atlanta alongside Southwest, JetBlue, and Spirit Airlines’ heavy presence in Ft. Lauderdale and you're bound to have a planeload of customers.  

9. Atlanta (ATL) – New York (LGA)

As the busiest airport in the world, it’s no surprise to see ATL well represented on the busiest air routes list. Add New York's LaGuardia airport to the equation, and you have a combo that flew 2.387,693 passengers on 19,348 scheduled flights. 

8. Denver (DEN) – Los Angeles (LAX)

This city pairing is the one with the highest year-on-year average increase of 7.3 %, so if you were wondering why there are less empty seats on this route, there’s your reason. Frontier’s rapid growth in the market and connections through DEN certainly add to the passenger load factor on this busy route that made 18,869 trips with 2,519,541 passengers onboard.

7. Los Angeles (LAX) – Seattle (SEA)

Los Angeles figures prominently on this list and here’s another route that links LAX with another big West Coast market­—Seattle. This Alaska Airlines heavy route offers departures from Seattle-based airlines nearly hourly. Pair that alongside nonstop flights from American, United, and Delta, and, voila, you have one of the busiest in the nation with 22,766 departures transporting 2,768,035 customers.

6. Las Vegas (LAS) – Los Angeles (LAX)

It looks like many people would rather fly than make the roughly 4-hour drive between these two flashy cities. With choices from six different airlines, there is healthy competition on this route that routinely brings prices below the $100 roundtrip mark. While the ticket prices might be low, the passenger loads remain high, as this 6th busiest route served 2,823,411 passengers onboard 24,575 flights.

5. Atlanta (ATL) – Orlando (MCO)

With 18,142 flights between Atlanta and Orlando between five airlines, 2,836,474 passengers made their way across the state border on this leisure market mega route. I’d venture a guess that most of the traffic came via feeder flights from other parts of the country through ATL and onward to top tourist destination Orlando. If this is the last segment on your journey to Disneyworld, expect a flight as full as the line for Space Mountain.

4. Los Angeles (LAX) – Chicago (ORD)

Hub to two major airlines, American and United, it was only a matter of time before we saw Chicago O’Hare pop-up as an airport partner on one of America’s busiest routes. Pair with the busy LAX and you've got a match guaranteed to be popular among passengers. This nonstop city-to-city route flew 17,251 times last year, transporting 2,927,492 travelers between the two destinations.

3. New York (LGA) – Chicago (ORD)

Both business and vacation travelers alike frequent this major route between two of the country’s largest markets. With peak-hour shuttle services joining the two airports in addition to flights with onward connections, this pairing is always near the top of busiest routes. Last year 3,118,651 customers boarded 29,169 commercial aircraft servicing these airports. 

2. Los Angeles (LAX) – San Francisco (SFO)

Keeping it instate, this California route has the most number of flights per year between any two destinations in the United States. With over 10,000 more departures than the LGA to ORD route, this second busiest route in the nation served 3,507,702 passengers on a whopping 40,120 flights.

1. New York (JFK) – Los Angeles (LAX)

Not a huge surprise at number one with this city pair linking the country’s two largest metropolises. For those keeping score at home, this top route is LAX’s sixth appearance on the list. LaGuardia may handle the majority of NYC’s domestic traffic, but JFK’s cross-country options to LAX claims the crown for the busiest in the United States. While the number of annual flights is lower than others on this list at 26,198, the wide-body aircraft used to serve these cities pack in the passengers, transporting 3,531,613 transcontinental flyers over the last 12 months. 

Other Findings

While the United States is still the leading worldwide market in aviation, the Asian marketplace continues to make a strong surge in passenger traffic. In fact, out of the top 10 busiest routes in the world, nine are within the Asian continent. Leaving the Sydney (SYD) and Melbourne (MEL) connection in Australia, as the only non-Asian route to crack this year's top 10.

A North American airport doesn’t make an appearance until number 19, and that’s south of the border between Cancun (CUN) and Mexico City (MEX). You’ll have to venture down to 30th overall before the United States’ top route between New York (JFK) and Los Angeles (LAX) cracks the lineup. New York (JFK) to London (LHR) is the busiest international route including a U.S. airport. And while you'll find it down at 49th on the list, it’s the worlds most profitable. As the industry’s first billion-dollar route, British Airways took it to the bank on this lucrative city-to-city pair over the last 12-months.

For those of you curious as to what the busiest route in the world is over the last year, South Korea's (280mi/450km), domestic short-hop from the island of Jeju (CJU) to the capital Seoul (GMP), remains at the top spot with over 13.4 million passengers on nearly 66,000 flights annually. That's over 4 million more flyers than the number two spot on the world’s busiest list, and an average of one flight every eight minutes!

Header image by stockphoto mania via shutterstock.com

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