Efforts to create a train horn quiet zone in North Lawrence have been dealt a blow.

City staff members confirmed Friday that a project to safely allow evening trains to travel through North Lawrence without blowing their horns will cost anywhere from $80,000 to $120,000 more than originally expected.

“This is something the city would have to pay for because there’s really no way we could compel the railroad to pay for the improvements,” said Jonathan Douglass, a city management analyst.

The extra expense comes after staff members with the city and the Union Pacific Railroad discovered that the federal regulations governing train horn quiet zones require the installation of more advance train-detection systems to warn motorists and pedestrians of oncoming trains.

The railroad crossings at North Seventh, North Eighth and North Ninth streets already have the advanced warning system, which flashes lights and rings bells earlier depending on the speed of the train. But the crossing at North Third Street has an older warning system that would have to be replaced. The railroad estimates the system would cost $80,000 to $120,000 to install.

Those costs would be in addition to about $60,000 worth of work needed to build medians at North Third and North Seventh streets to prevent motorists from driving around the railroad crossing arms.

Members of the North Lawrence Neighborhood, though, said they would urge the city to move ahead with the project, despite the extra costs.

“We think it still would be a good investment,” said Ted Boyle, president of the North Lawrence Improvement Assn. “It would be another thing to promote North Lawrence. People would be more prone to have a business or a home here.”

Boyle brought the idea to city commissioners more than a year ago after new residents of North Lawrence began expressing concerns about the number of train horns that blared each night.

Union Pacific runs between 60 and 100 trains per day through North Lawrence. The quiet zone would allow trains to travel through the area without blowing their horns from 10 p.m. to 7 a.m. The neighborhood originally had asked for a 24-hour quiet zone, but the company officials who operates buses for Lawrence public schools said they believed that would create safety concerns.

Douglass said city commissioners will be presented with the new information in the next several weeks and asked whether they want to proceed.