Construction activities begin on MaineDOT’s Bangor I-95 bridges replacement project

Bridge modernization to improve safety, clearance and long-term performance

Construction activities are underway on the Maine Department of Transportation’s (MaineDOT) Bangor I-95 Bridges Replacement project. Preparatory works have begun in the median between the northbound and southbound lanes over Stillwater Avenue.

Mott MacDonald is the designer on the project, working as part of the design-build team with Cianbro, the construction contractor, and geotechnical partner, Haley & Aldrich. Our role involves the design of the replacement bridges and associated infrastructure, including the development of construction staging and traffic management strategies that allow work to be delivered while maintaining traffic on I-95. By eliminating the use of a temporary bridge during construction, the design prioritizes safety, constructability and long-term performance while minimizing disruption for road users and surrounding communities.

The project involves the replacement of three existing bridges, originally constructed in the 1960s and now nearing the end of their service life. These include two I‑95 bridges (northbound and southbound) over Stillwater Avenue and the Kenduskeag Avenue bridge over I‑95.

I-95 Bridges over Stillwater Avenue (image credit: Cianbro)

Kenduskeag Avenue Bridge over I-95 (image credit: Cianbro)

At Stillwater Avenue, the existing multi-span bridges will be replaced with new single-span steel girder bridges, simplifying the structures and reducing maintenance requirements. At Kenduskeag Avenue, the existing four-span bridge will be replaced with a shorter, higher-clearance structure, improving overall performance and safety.

Construction is being carefully phased to maintain traffic on I-95 throughout project delivery, an approach developed collaboratively during the design-build process. The replacement bridges and construction sequencing were designed using a median crossover and temporary traffic diversions – without the need for a temporary bridge – allowing work to progress while minimizing extended detours and maintaining access for local communities and businesses.

The project will deliver long-term value for the traveling public and surrounding communities, improving safety and traffic flow along the I‑95 corridor and reducing bridge maintenance needs through simplified, more durable designs.

“Our team took a collaborative approach to developing an innovative and efficient solution that keeps traffic moving while we deliver more resilient, lower-maintenance infrastructure,” said Jeff Long, New England portfolio manager at Mott MacDonald. “By carefully planning the construction approach, we’re helping to reduce disruption and create a safer, more reliable route for the long term.”

As the project moves into its next phases, we will continue to work closely with MaineDOT and our project partners to support safe, efficient delivery along this vital corridor. The overall project is expected to be completed in 2029, delivering long-lasting improvements to the safety and resilience of the I‑95 corridor for the Bangor community.