Work can continue on the North Rampart Street streetcar line project after a federal judge Friday turned down a request to halt construction while a group of activists sues to require detailed archeological and environmental studies of the project.

In denying a temporary restraining order to halt the project, U.S. District Judge Nannette Jolivette Brown said the plaintiffs had not shown they would be able to succeed in their case at a full trial.

Brown said they had not offered evidence that federal dollars are involved in the project — a key requirement for them to succeed.

“You can’t come forward with unsubstantiated allegations,” Brown said. “I haven’t seen so far any evidence. I’ve only heard arguments.”

The plaintiffs, who include the transit-focused Bring Our Streetcars Home group, the anti-racism group People’s Institute for Survival and Beyond, representatives of American Indian tribes and nearby residents, have argued that under federal law, studies to determine whether the project would disrupt archeological sites, harm historic buildings or cause environmental damage should have been conducted before construction began.

The suit names the Regional Transit Authority and the private agency that manages its operations, Transdev, as well as several federal agencies as defendants. Those agencies all argued the studies are not needed during Friday’s hearing.

Such studies are required of projects paid for with federal money — the claim that Brown said those bringing the suit were unable to prove Friday.

They argued that even though the $41.5 million cost of the streetcar line will come from local funds generated by a 2010 bond issue, the use of federal money to study the feasibility of a line that would have included that route and the general use of federal dollars by the RTA mean the project should have to go through those reviews.

The federal government’s involvement in the earlier study does not mean “the federal government is saddled with that project forever,” Federal Transit Administration attorney Jason Bigelow said.

That’s particularly true in this case, he said, because after the study was completed, the federal government repeatedly turned down requests to fund the North Rampart streetcar line on the grounds that it was not cost-effective.

Attorneys seeking to block the construction also argued that the value of the artifacts that could be harmed by construction showed the project should be halted.

The potential to damage important relics buried under North Rampart or to disrupt early burial grounds in the area meant a temporary restraining order was crucial to protect historically significant artifacts, said Lucas Morehouse, an attorney for the plaintiffs.

“The irreparable injury is the historic value of the data that would be destroyed,” he said. “It’s priceless, utterly priceless.”

But attorneys for the RTA noted that the route would cover ground that already has been paved over and that in fact had a streetcar line decades ago, meaning that whatever damage could be done already has occurred. The transit agency has said it will have an archeological consulting group on call should anything of historic significance be found during construction.

Work on the 1.6-mile streetcar line from Canal Street to Elysian Fields Avenue along North Rampart and St. Claude Avenue began Monday as crews began erecting traffic barriers. But after the lawsuit was filed later in the day, the project was suspended until Brown could rule on the TRO request.

Archer Western, the contractor on the project, will be notified it can move forward with construction, RTA officials said Friday.

The project has drawn criticism from a number of nearby residents, who warned about the impact of construction and other issues at a forum last week, and from some transit advocates, who said plans to have the streetcars mix with other traffic will create an inefficient system. They have called for tracks to run in designated streetcar-only lanes to provide higher-speed service.

Bring Our Streetcars Home President Jack Stewart defended the need for more studies but said his opposition to the project centers around those kinds of transit concerns. The project will mainly benefit tourists rather than residents and should have been planned to provide efficient service with cars running in the neutral ground, he said.

“We’re an advocate for this line. We’re just an advocate for it being done right,” he said.