BART's new wheel profile reduces noise pollution

Bay Area Rapid Transit's (BART) new reduced-contact wheel profile has helped cut down on interior noise in trains.

The new wheel profile has led to a 15-decibel drop in onboard noise, agency officials said in a news article on BART's website.

"Fifteen fewer decibels may not sound like a big jump, but remember that decibels — like the Richter Scale — are measured logarithmically, not linearly," BART officials said, adding that the equipment is "many times quieter than before."

Currently, 13 percent of BART's legacy fleet has been outfitted with the new wheel profile. By the end of 2019, agency officials expect to have outfitted 90 percent of the fleet. BART announced the design of the new wheel profile in August 2016.

The agency's "Fleet of the Future" cars will roll off the assembly line with the new profile. The next generation of rail cars also will feature "micro-plug" doors to help seal out noise.

Agency crews will perform surface grinds on the rails to further cut down on screeching. The "rail optimization plan" will include three phases over five years, with six grinding passes per phase across the entire 235-mile system.