A federal judge is ordering a pause on construction of a stretch of road in Derry after finding that state and federal highway planners failed to follow proper regulations when they altered a proposed rail trail.

The ruling is a victory for the Committee to Save the Derry Rail Trail Tunnel, an advocacy group that argued the state’s shift in design from an underground tunnel for bicycles and pedestrians to a curvy ramp and crosswalk across a 6-lane road violated federal law.

The judge’s order means that the state’s Department of Transportation must decide now whether to appeal, perform a new analysis on the competing rail trail designs, or simply opt to build the underpass, which was its initial proposal.

“We’re not over the goal line yet,” said Bob Spiegelman, a cyclist and member of the rail trail advocacy group. “Hopefully DOT will just come back and regroup, and rather than waste more money and time trying to fight this, we’ll just go ahead and do the right thing and build according to the original approved plan.”

In 2024, state highway officials formally submitted the new design for the crossing. Instead of burrowing under the new exit ramp off of Interstate 93 in Derry, the revised plan called for a ramp leading to the elevated roadway. Officials estimated it would save approximately $770,000 over the tunnel design.

Opponents derided the “spaghetti loop” nature of the path, and said it, along with the road crossing, was unsafe.

An existing rail trail begins in Salem and heads north along a paved, protected route into Derry. But there is an approximate one-mile gap where the Derry trail ends and the Londonderry rail trail starts again. Portions of the proposed connecting strip of trail happen to cross an existing rail corridor that was deemed historically significant by the state in 2009.

The Manchester and Lawrence Railroad was “an engineering feat in its day—the work of Irish laborers who cut through New Hampshire’s granite hillsides with hand tools and blasting powder,” Judge Paul Barbadoro wrote in his opinion.

Under existing federal regulations, highway projects that disrupt historically significant assets are required to undergo an evaluation to see if any alternatives plans could be implemented to lessen any impact. Barbadoro ruled that because that harm analysis wasn’t performed, construction on an approximate 1 mile stretch of the new road must be paused.

William Cass, New Hampshire’s transportation commissioner, said his office is still reviewing its options. “The Department is disappointed by the order. We are working with the NH Attorney General’s Office to determine our next steps,” he said.

Construction has already begun on other portions of the new exit ramp, and DOT initially said that work on the section of road that would intersect with the rail trail could begin as early as August.

The one-mile stretch of road that’s being constructed as part of the second phase of the project was originally projected to cost $33 million, while the total cost of the new exit ramp and connecting roads are forecasted to top $134 million, portions of which are being paid for by the 2021 bipartisan federal infrastructure law.