Advocates Win Tunnel Case for Derry Rail Trail

Bicycling and pedestrian tunnel to be built under new Exit 4A access road in New Hampshire

Published on Feb. 11, 2026

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After a lawsuit filed by the Committee to Save the Derry Rail Trail Tunnel and the Rails to Trails Conservancy, advocates have secured a settlement to build a bicycling and pedestrian tunnel under a six-lane access road for the new Exit 4A off Interstate 93 in North Derry, New Hampshire. The state had previously scrapped the tunnel plan in favor of a steep climb to a crosswalk, but a federal judge ruled that the alternatives violated laws protecting historic sites.

Why it matters

The tunnel is seen as the safest and most accessible option for the Derry Rail Trail, which is part of a larger plan to create a statewide network of rail trails in New Hampshire. The legal battle highlights the importance of protecting historic rail corridors for public use, which has implications for rail trail projects across the country.

The details

In 2019, the state and federal government approved a plan to build a tunnel for the Derry Rail Trail under the new Exit 4A access road. But in 2021, the state unilaterally scrapped the tunnel plan and submitted new proposals to the Federal Highway Administration, which approved them within one business day. The Committee to Save the Derry Rail Trail Tunnel and the Rails to Trails Conservancy sued the state DOT and Federal Highway Administration, arguing the alternatives violated laws protecting historic sites. A federal judge agreed and issued an injunction, ultimately leading to the settlement to build the originally planned tunnel.

  • In 2019, the state and federal government approved the tunnel plan.
  • In 2021, the state scrapped the tunnel plan and submitted new proposals that were quickly approved.
  • In June 2024, a federal judge issued an injunction to prevent construction that would damage the historic district.
  • On Monday, the settlement agreement to build the tunnel was signed.
  • Construction on the tunnel and Exit 4A is expected to be completed by spring 2028.

The players

Committee to Save the Derry Rail Trail Tunnel

A local advocacy group that sued the state DOT and Federal Highway Administration to protect the original tunnel plan for the Derry Rail Trail.

Rails to Trails Conservancy

A national nonprofit organization that joined the lawsuit to protect the historic rail corridor and ensure a safe walking and biking path.

U.S. District Judge Paul Barbadoro

The federal judge who issued an injunction to prevent construction that would damage the historic district and urged the state and federal governments to settle the case.

Bill Cass

The New Hampshire DOT Commissioner who said the department is pleased to have resolved the matter and is eager to proceed with building the tunnel.

Dave Topham

The president of the New Hampshire Rail Trails Coalition who served for decades on the Complete Streets Advisory Committee advising the DOT.

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What they’re saying

“We're very glad to see this get over the finish line here, after four-and-a-half years.”

— Dave Topham, President, New Hampshire Rail Trails Coalition (InDepthNH.org)

“We are pleased this matter has been fully resolved. Reaching this agreement helps minimize delays and allows us to move forward with construction. We are eager to proceed with building the tunnel and completing the project, which is expected to remain on schedule.”

— Bill Cass, New Hampshire DOT Commissioner (InDepthNH.org)

“This lawsuit could have been prevented entirely had the New Hampshire DOT and (the Federal Highway Administration) stuck to the original design that included the tunnel. Instead, they made a back-room deal that cost time and money.”

— Alex Bernhard, Member, Committee to Save the Derry Rail Trail Tunnel (InDepthNH.org)

“It represents an important victory for rail trails across the country.”

— Ryan Chao, President, Rails to Trails Conservancy (InDepthNH.org)

“We're one step closer to getting another leg of the Granite State Rail Trail completed.”

— Kevin Gordon, President, Derry Rail Trail Alliance (InDepthNH.org)

What’s next

Once the Exit 4A-related construction and underpass are complete in spring 2028, Derry and Londonderry plan to complete and connect their rail trails along the historic right-of-way, which stretches from the Massachusetts border with Salem to Manchester. The rail trail can then connect to others that cross the state.

The takeaway

This case highlights the importance of protecting historic rail corridors for public use, such as rail trails, and the legal battles that can arise when transportation projects threaten these valuable community assets. The settlement to build the originally planned tunnel represents a victory for rail trail advocates and sets a precedent for preserving safe and accessible paths for pedestrians and cyclists.