An activist group that opposes the construction of Interstate 73 has filed suit in Richmond federal court to stop funding for the project.

The legal action on Tuesday by Virginians for Appropriate Roads cites what it calls I-73's "significant, irreversible adverse effects on natural scenic, and econological resources..."

Last April the federal government authorized Virginia to begin designing the highway, a futuristic link between the Roanoke Valley and the North Carolina line with an estimated $4 billion price tag.

But on Tuesday, Andrea Ferster, a Washington-based attorney for the opposition, asserted that the chances the lawsuit to be successful "are substantial." She added, "The whole need for this project was based on the idea that it would be built all the way from the North Carolina border to Portsmouth, Ohio. But federal officials acknowledge there's little likelihood that the entire project will be built." In that case, she said, segments such as the one connecting North Carolina to Roanoke aren't as crucial as other potential road projects that could be built with I-73 funds.