The U.S. Department of Transportation is finalizing regulations requiring that many new commercial aircraft be more accessible to people with disabilities.

The agency said that new single-aisle airliners with 125 or more seats will need to offer lavatories “large enough to permit a passenger with a disability and attendant, both equivalent in size to a 95th percentile male, to approach, enter, and maneuver within as necessary.”

Until now, accessible lavatories have only been mandated on airplanes with more than one aisle, but increasingly, single-aisle aircraft have been used for longer flights. The smaller planes accounted for 86% of flights between 1,500 and 3,000 miles in 2021, the Transportation Department said, double the level in 1991.

Such flights can last for four hours or more, forcing people with disabilities to resort to extreme measures such as dehydrating themselves, using adult diapers or catheters in order to fly, the agency indicated.

“Traveling can be stressful enough without worrying about being able to access a restroom; yet today, millions of wheelchair users are forced to choose between dehydrating themselves before boarding a plane or avoiding air travel altogether,” said Transportation Secretary Pete Buttigieg. “We are proud to announce this rule that will make airplane bathrooms larger and more accessible, ensuring travelers in wheelchairs are afforded the same access and dignity as the rest of the traveling public.”

The rule issued under the Air Carrier Access Act will take effect 60 days after it is published, but the changes will phase in over several years.

New single-aisle aircraft with 125 seats or more delivered three years after the rule is in place must include grab bars, accessible faucets and other features. In addition, on-board wheelchairs must be able to partially enter the lavatory adequately to allow an individual to transfer to the toilet, among other improvements.

The mandate to include larger, accessible lavatories will apply to new single-aisle aircraft with 125 seats or more ordered 10 years or delivered 12 years after the effective date of the rule. They will also be required for any new aircraft designs filed one year after the effective date.

The Transportation Department first proposed lavatory improvements to better serve airline passengers with disabilities in 2020 and subsequently issued a secondary proposal in 2022.

Meanwhile, federal officials have indicated that they are working on a rule to allow travelers with disabilities to remain in their own wheelchairs on commercial flights.

Separately, in another bid to improve accessibility on planes, United Airlines said last week that it is the first airline to add Braille to the interiors of its aircraft. The airline said it expects to add the signage marking rows, seat numbers, lavatories and more to its entire mainline fleet by the end of 2026.