Chains hang between old Metro cars in the District in June 2017. When WMATA purchased new 7000 series trains, they were not outfitted with chains between cars, which may have been a factor in at least two sight-impaired riders falling between cars. (Bonnie Jo Mount/The Washington Post)

To the casual listener, the declaration emanating from the speakers inside Metro’snewest trains is an exercise in the painfully obvious.

“This is a 7000-series train,” the automated system announces as the doors open. Then, the doors close, the train moves onto the next station, and the message repeats.

Again. And again.

“Why does @wmata think everyone wants to know they’re riding a 7000 series train?” tweeted one rider last week.

The question, it turns out, is a common one — at least judging by riders who have chimed in on Twitter recently.

“Why do you guys announce ‘this is a 7000 series train’ at every stop? Just tell me where the train is going. No one cares about the type of train it is.”

“Doesn’t really seem like the most useful information.”

“I am going to lose my mind if I have to keep hearing it.”

But the backstory behind the announcements is one of huge stakes — public safety, an expensive infrastructure investment and a battle with the federal government that has resulted in costly changes to Metro’s newest fleet of rail cars.

On the most basic level, the audio announcements are meant to serve as a message to people with visual impairments — warning them to take special care while boarding the train. The warning is needed because of a design feature of the new trains, a change in the barriers that are used as safeguards in the space between train cars. Some of the gaps between the new rail cars are equipped with rubber barriers. Previous models feature a pair of chains clipped to the car on either side that are meant to alert a person waving a hand or cane that they should not move forward.

The rubber flaps are designed to be easier and safer for Metro employees working with the trains in the rail yard, but they also can increase the risk of blind or visually impaired rider falling in the space between the cars.

In the past two years, there have been at least two reported incidents of visually impaired riders mistaking a gap between cars for a doorway into the train and accidentally stepping off the platform and falling onto the rail bed.

So, the automated announcements are intended to be Metro’s quick, subtle heads-up to those riders, who may have heard through disability advocacy communities that the 7000-series trains pose an extra safety risk for them.

“It is focused on people with a visual disability, so we’ve reached out to that community, to let them know that that’s the type of announcement that we’ll be making,” Metro General Manager Paul J. Wiedefeld said. “For the general public, I understand that it may not be as relevant to them.”

The announcements also are a capitulation to the Federal Transit Administration, which last month said it is considering withholding federal funding from the transit agency at the end of this year if Metro doesn’t retrofit all the 7000-series cars with a better barrier.

The rail-car manufacturer, Kawasaki, has said it can’t meet the December deadline to install new barriers.

After a series of safety concerns, Metro will pay to retrofit nearly 200 of the system’s new 7000-series rail cars with chain barriers to help prevent people with impaired vision from falling between cars. (Marvin Joseph/The Washington Post)

So, in the short-term Metro officials are trying to allay the concerns of the FTA. They’ve had in-person discussions about striping the existing gap between car barriers with reflective tape to alert people who might have low vision. And they’re using the audio announcements.

The announcements also are being played occasionally at stations, warning blind riders who navigate the subway platforms using their canes to be careful and tap the floor of the train car before boarding — just to be sure that they are indeed about to walk onto a train and not fall between the gap.

“It was one of the commitments we made to the FTA,” Wiedefeld said. “They asked for a plan to deal with this issue in the interim.”

Freddie Peaco, president of the D.C. Council of the Blind, said the announcements are a positive development and will help increase safety.

But Kenneth Shiotani, a senior attorney at the National Disability Rights Network who was among the first to report the safety risk to the FTA, said the audio announcements won’t necessarily help out-of-town visitors with visual impairments. (And, he notes that blind and visually impaired tourists flock to the District in part because the transit system is so much easier for them to navigate than those in other cities.)

Those riders, Shiotani said, won’t know that “ ‘This is a 7000 series train’ is supposed to serve as code for ‘Watch your step extra-carefully.’ ”

Jeannette Gerrard, a 68-year-old visually impaired woman who fell onto the tracks at the Van Ness-UDC Metro station in May, said she’s glad the announcements have been added to the system — but it’s still not enough to make the trains safe.

“Anybody could fall. It’s not just for blind people. It’s for anyone,” Gerrard said of Metro’s plan to retrofit the cars with chain barriers. “They just need to get this stuff done.”