BART stations may be known for their grime but they’re getting cleaner, especially the elevators and restrooms, according to rider survey results released by the transit agency Wednesday.

Overall, 64.2% of riders surveyed were satisfied with the cleanliness of the stations between April and June, an improvement of 2 percentage points over the previous year.

Elevators, which have frequently been used as restrooms, were rated good or excellent by 58.8% of passengers surveyed, compared to 42.8% the same quarter of 2018.

BART officials credit a program that stations attendants inside elevators at Civic Center and Powell stations, dissuading people from misusing them. The program started in April 2018 and “has virtually eliminated inappropriate behavior” in those elevators, according to BART officials.

BART plans to expand the elevator attendant program to the Embarcadero and Montgomery Street stations this fall.

Riders also gave BART improved rating for the cleanliness of station platforms, with good or excellent ratings rising to 69.8% from 63.3% a year earlier.

Even restrooms, which make many a BART rider squeamish, ranked higher, with 40.6% rating them good or excellent, up from 35.2% the prior year.

Stairwells, escalators and concourses have been part of the passenger survey only since July 2018, but they also were rated cleaner.

Riders gave concourses a 65.3% thumbs-up rating versus 62.7% nine months earlier. Escalator cleanliness rose to 65.3% from 62.7%, and stairwell cleanliness climbed to 60.2% from 56.8%.

Between 5,000 and 6,000 riders fill out the surveys on BART trains every three months. They’re used as part of BART’s quarterly performance reports, which measure everything from cleanliness to delays to how many escalators are broken. The latest will be presented to the Board of Directors at its Thursday meeting.

BART’s dismal customer satisfaction ratings hit all-time lows in the past two years, prompting renewed efforts to clean up stations.

“We are committed to improving the customer experience through cleaner stations and have revamped our approach to include focused overnight cleanings of our busiest stations,” BART General Manager Bob Powers said in a statement.

BART plans to hire 15 more cleaners over the next six months.

Michael Cabanatuan is a San Francisco Chronicle staff writer. Email: mcabanatuan@sfchronicle.com Twitter: @ctuan