For seven years, the floor-to-ceiling windows at the back of Pam Steinhagen’s Lakeville house have often been filled with an unlikely view: a long line of parked railroad cars.

In warm weather, some of the cars have filled with stagnant water, attracting swarms of mosquitoes. When they’re moved from one stretch of track to another, they can block the neighborhood’s only exit. And teenagers often test their luck climbing up to sunbathe or running down the line of cars, jumping the gaps as they go.

“Basically, this is a rail yard,” said Theresa Johnson, Steinhagen’s neighbor. “It’s just a matter of time before someone gets hurt or killed.”

Across the country, lessened demand for products like frac sand has taken freight trains out of commission. In 2015, total U.S. carload traffic was down 6 percent from the year before, according to the Association of American Railroads. The group credits that drop, in part, to declines in the energy and manufacturing industries.

With less demand for trains, rail yards fill up and companies turn to unused stretches of track like the one behind Steinhagen’s house for long-term storage. The practice has raised concerns among locals about everything from aesthetics to environmental impact.

The track in Lakeville, which at one time was targeted for a potential county greenway, is owned by Canadian Pacific but operated by a Lakeville company called Progressive Rail. Dave Fellon, the company’s president, declined to comment. In 2012, he told the Star Tribune that a sluggish economy was keeping the cars parked.

Railroads fall under federal authority, but there are no safeguards to keep unused cars from languishing in one spot. Minnesota’s U.S. Sen. Amy Klobuchar and U.S. Rep. John Kline introduced bills this session that would require rail carriers to have a storage plan approved by the Surface Transportation Board, but neither measure has moved out of committee.

“Federal law just pre-empts this entire field of law, leaving individual citizens and communities completely helpless to railroads that are largely unresponsive to local concerns,” said Anders Blewett, an attorney and former Montana legislator who fought against rail car storage along the Missouri River.

Blewett introduced a joint resolution in 2009 publicly censuring the BNSF Railway for storing cars indefinitely along the river. Though the resolution didn’t pass, public opposition finally got the approximately 1,000 cars moved in 2010 — about three years after they arrived.

A similar outcry arose in New York state, when Iowa Pacific Holdings made plans to store oil tankers on tracks running through protected land in the Adirondack Mountains. Faced with continued opposition from environmental preservation advocates, the company backed down this fall.

In Lakeville, long-term rail car storage has been on the city’s legislative agenda for years. But there’s not much the city can do beyond supporting measures at the federal level.

“Ideally, we’d like to see them not there at all,” said City Administrator Justin Miller. “But even if there was a time limit, I think that would be a good first step.”

For now, those closest to the tracks are still worried. They’re anticipating diminished property values or not being able to sell their houses at all. They’ve noticed oily residue dripping from the cars to the ground, and have wondered whether it’s safe.

Steinhagen, who runs a day care out of her home, said she and her neighbors feel responsible for “policing” the cars for trespassers and graffiti.

“We didn’t purchase our properties knowing there would be rail storage in our own backyard,” said resident Jeff Vanden Busch. “We’ve taken it for seven years, and it’s time something happened.”