An RTD A Line commuter rail train at the 38th and Blake Street station in Denver.

Hart Van Denburg/CPR News

After blaring their horns for some three years, the Regional Transportation District’s A Line trains will finally fall mostly silent as of March 1 as they travel between Denver International Airport and downtown.

Denver Mayor Michael Hancock made the announcement at a Union Station press conference Friday afternoon, flanked by RTD executives.

"I have sat on the back patios of residents," Hancock said. "I have listened as horns have blared all hours of the day and night. And so today, recognizing that we get a sign-off on the quiet zones is huge."

Because the A Line’s crossing gates came down too early and stayed down too long when the line opened in April 2016, federal regulators required operators to blare their horns at every crossing. Residents along the line have complained about the noise for years.

“We’ve been grateful for your patience to this point,” said RTD General Manager and CEO Dave Genova said.

But the A Line won’t be completely quiet quite yet: Trains will still have to sound horns in Aurora until regulators sign off on crossings there, Genova said. That process will likely take a few more weeks.