PROVO — A 2-year-old federal regulation regularly jolts Sherrie Spencer from her sleep at night.

The regulation requires trains to use more and longer horn blasts at road crossings — day and night — upsetting the lives of Spencer and others who live near the railroad tracks that cut through central Provo and then snake north along I-15.

The problem will only intensify when commuter rail comes to town in the future, possibly tripling the number of trains.

Silencing the horns could be expensive.

"We're being very aggressive in trying to resolve this issue," Provo Mayor Lewis Billings said. "The early estimate is that it could cost $1.5 million."

The money would be spent on additional gates to meet safety regulations that can trigger quiet zones established by the Federal Railroad Administration in 2005.

The city is setting aside $250,000 in the budget and is applying for a federal grant to help offset the costs, city council member Cindy Richards said.

Spencer spurred the city to action in March when she spoke passionately during a city council meeting on behalf of a group called "Quiet Trains for Provo."

The group of more than 150 residents has printed T-shirts with the logo of a friendly little train they named "Hush."

Hush has a twofold mission — to quiet locomotive horns and to do so without raising a racket against the city or the railroads.

Quiet Trains wants "to work in a cooperative, professional and relentless manner with the city" to ameliorate the "noise nuisance" that has "made life for those living closest to the tracks difficult and miserable," according to an e-mail sent to residents.

Billings, a champion of commuter rail service to Provo, sent the city's public works director to Irving, Texas, to learn how that city established quiet zones.

Provo is also trying to learn from Salt Lake City, which established train quiet zones near The Gateway.

Weber and Davis county communities are trying to do the same. They are asking the Federal Railroad Administration to approve quiet zones where UTA's FrontRunner commuter rail line will run at 79 mph between Weber County and Salt Lake City beginning in 2008, according to the Associated Press.

Billings hopes commuter rail will reach Provo by 2012 or sooner.

Spencer and the rest of the Quiet Trains group want to be sure Provo has quiet zones long before then.

Railroad crossings at 200 West, 500 West, 700 West, 900 West and 820 North are all in residential neighborhoods and all have two gates, one on each side of the tracks.