The current Salt Lake City International Airport was designed to handle just 10 million passengers a year — but now serves 25 million. Still, it performed better than average in annual J.D. Power rankings of customer satisfaction for airports in North America released Wednesday.

Salt Lake finished at No. 11 among 27 large airports. Its overall score was 779 out of a possible 1,000 — a bit above the average 765 score for large airports.

That score could easily rise in the future. The first phase of terminals and concourses for the new $3.6 billion airport — being built alongside of the existing facility — are scheduled to open in a year.

Until then, the airport is crowded — and sometimes is standing-room-only at gates, has lines out the door at bathrooms, and security lines in Terminal 2 sometimes stretch back across a pedestrian skybridge all the way to the parking garage.

“We are pleasantly surprised to see Salt Lake City International Airport ranked as high as it did,” said airport spokeswoman Nancy Volmer.

“We are operating out of a facility that was built nearly 60 years ago and is experiencing intense overcrowding. Kudos to our staff who do a tremendous job in taking care of the current facilities to ensure a pleasant travel experience for our passengers,” Volmer said.

Michael Taylor, an analyst for J.D. Powers, said only part of the satisfaction score comes from passenger experience in concourses with such things as comfort of seats and cleanliness of bathrooms. Much of it comes from how easy the access to the airport is, and he says Salt Lake City excels at that.

He notes that the airport is just five minutes or so from downtown Salt Lake City.

“Contrast that with any other metropolitan airport, where it’s sometimes a long, long way to the airport,” he said.

He notes that Salt Lake’s easy accessibility is much like airports in Las Vegas and Indianapolis, “and both of those have been winners in recent years. So that accessibility is a real advantage…. Things like that have kept the score high.”

The highest ranking large airport this year was Portland, Ore. with a score of 833 (where current Salt Lake City Airport Director Bill Wyatt was its former director), followed by Dallas Love Field (826) and Tampa, Fla. (822).

The lowest ranking large airports were New York LaGuardia (662), Honolulu (719) and Ronald Reagan Washington National (733).

In the even larger “mega airport” category, Detroit Metropolitan Airport topped the rankings with a score of 786 (only a bit higher than Salt Lake’s score of 779). At the bottom was Newark Liberty (N.J.) with a score of 695.

Among medium airports, Indianapolis was No. 1 with a score of 833. The worst was Kahului Airport (on Maui in Hawaii) at 754.