Air passengers everywhere are tired of cramped, dirty and smelly airport bathrooms, to hear travel experts tell it. So the Minneapolis-St. Paul International Airport is giving its restrooms an ambitious overhaul that will stretch over the next decade and cost about $12 million in the next three years.

Prototype restrooms on the E and F concourses at MSP provide a sense of what's to come. They're bathed in natural light and feature quartz countertops and terrazzo floors, expansive stalls and original mosaic artwork. They're more Apple store than public toilet.

"You expect an airport bathroom to be not very clean," said Kaitlyn Croatt, a University of Minnesota interior design student who was returning from a Florida trip last week. As she walked through the F concourse bathroom, she declared, "This is not what I was expecting. I love it."

The renovations will mean fewer restrooms overall in Terminal 1 (Lindbergh), where some will be closed, consolidated and reconfigured. But the number of stalls will be about the same, and the restrooms will be in better locations, according to Alan Howell, senior airport architect for the Metropolitan Airports Commission, which operates MSP.

"We're putting restrooms in locations that make more sense for passengers," he said. "Every five gates, you should be running into a restroom." So that means 13 smaller restrooms on concourses E, F and C (from gates C1 to C10) will be consolidated into five facilities, but with roughly the same number of stalls, urinals and sinks.

All told, MSP has about 100 "sets" of restrooms in both terminals, but that also includes those outside secure areas, and employee areas beyond those serving the traveling public.

The price tag for this year's restroom overhaul is about $6.1 million. That includes a new set of restrooms slated to open next month on the south end of the Terminal 1 mall, with a second set on the northern stretch of the mall expected later in the year.

These facilities will replace the aging restrooms in the middle of the mall, including the men's room made famous by the 2007 arrest of former Sen. Larry Craig of Idaho, and those behind the Chili's and Subway restaurants. Restrooms will also be added in Terminal 2 (Humphrey) near Door 1.

More improvements

The restroom improvements are part of a broader renovation at the airport that includes an $18 million consolidation of security screening areas into two mega-checkpoints in Terminal 1, and the addition of about 50 new shops and restaurants. A $27.5 million expansion involving three new gates is underway at Terminal 2, as well. And just last month, the $2 million Escape Lounge opened in the mezzanine area of Terminal 1, a getaway for passengers willing to pay a fee.

But for most air travelers, clean restrooms remain the most primal desired attribute. "Cleanliness is extremely important," said airline industry consultant Ira Weinstein. "Men's restrooms tend to require more cleaning than women's restrooms, but for women, there's never enough stalls."

According to a 2015 report issued by the federal Airport Cooperative Research Program, "Restrooms in airport terminals that have lines or are cramped, dirty, smelly or ugly are no longer tolerable." And many travelers are not shy about posting their dissatisfaction with airport amenities (or lack thereof) on social media, potentially embarrassing the airport and city boosters.

Howell estimates that each restroom at MSP gets used 7,000 times a day, and he said the MAC has to consider not only families with children, but baby boomers traveling with aging parents, mothers who need facilities for nursing and lactation (about 55 percent of MSP's passengers are female), and service dog relief areas.

No more lurking outside

"Civilized waiting areas" are planned outside of some MSP's restrooms, too. "A lot of folks end up standing near the restroom door" while waiting for their travel companion, Howell said. "We'd rather have someone sit across the hall" on four or five seats where they can plug in their smartphone or tablet while waiting.

MSP planners chose terrazzo flooring because it doesn't have grout between tiles, which "always looks dirty even if it's clean," Howell said. Engineered quartz was used for the walls because it can be sprayed down easily. Hooks are near sinks so purses and laptops don't get wet, and niches in stalls can be used to safely stow these bags without the prospect of them being snatched away if left on the floor.

The overall restroom is more expansive, as well. "You can walk past others without bumping into them," Howell said. "The last place you want to bump into someone is in a restroom." This also helps with passengers in wheelchairs and others who have limited mobility, he added.

The prototypes have helped MAC staff determine how to design future restrooms. For example, although care was taken to select a quiet hand dryer, the devices still can cause hearing aids to overload. So paper towels will replace them in newer bathrooms.

Minnesota mosaics

Many of the amenities offered in the airport's prototype address universal needs of travelers, but there's one component that's distinct to MSP — mosaic artwork crafted by Minnesota artists. "First impressions count, and in many cases, [the restroom] is the first impression someone gets when they come here," said Robyne Robinson, director of arts and culture for the Airport Foundation MSP. (Airport officials say nearly half of all travelers at MSP are connecting to someplace else.)

The tile work invokes a sense of place by featuring landscapes and landmarks unique to Minnesota, and can be viewed just by walking by the restrooms. "With longer waiting times getting to and from your destination, it's an opportunity to educate and engage travelers," Robinson said.