SPS New England will replace the bridge that carries Interstate 495 over the river. There will be five travel lanes on the proposed northbound bridge and four on the southbound structure, including one lane in each direction allocated for future use. The project will also include complete removal of the existing structurally deficient bridge structures as well as road reconstruction and associated work such as drainage.

Construction and demolition will be carried out in multiple stages using temporary cross-overs to shift southbound traffic as required.

The work will need to minimise impacts to Merrimack River ecosystems. The river is home to shortnose sturgeon; their migratory patterns and spawning habitat mean that there will be work restrictions in the river.

“This highly travelled bridge provides an important regional connection between destinations for the public and we are looking forward to replacing this bridge so it can be used by future generations,” said highway administrator Jonathan Gulliver. “The innovative construction techniques will help to mitigate traffic and wetland impacts.”

Work is scheduled to begin in November for completion in spring 2022.