The Walk Bridge Program represents an ambitious undertaking by the Connecticut Department of Transportation. With a vision to enhance the safety and efficiency of rail operations—while also sustaining the economic and environmental vitality of the City of Norwalk and the surrounding region—the program plans to bring transformational improvements to the century-old commuter rail.


HNTB is serving as design consultant and designer-of-record for the Walk Bridge Program, which also serves as CTDOT’s first program to be contracted under the construction manager/general contractor delivery method.

The firm’s services include bridge, mechanical, electrical, track, high tower, catenary, geotechnical, signals and communication, civil, architectural, hydraulics and construction sequencing. HNTB was also responsible for preparing the environmental documentation and permit applications for the program.

Two of the infrastructure projects under the program include:

CP234 Interlocking/Danbury Branch Dockyard

As a precursor to the eventual Walk Bridge replacement, CTDOT combined two critical infrastructure enhancement projects on Metro-North Railroad’s (MNR) New Haven Line, the busy commuter route and link in the Northeast Corridor connecting Boston, New York and Washington D.C. The CP243 Interlocking, consists of a new four-track universal interlocking, while the other project, the Danbury Branch Dockyard, provides electrification and additional siding tracks.

Further improvements include the replacement of 100-year-old catenary structures, approximately 4,500 feet of track reconstruction, signal and communication upgrades, new drainage structures, slope stabilization, and a bridge replacement.

Other aspects of the projects and overall program will not only advance Norwalk’s railroad transportation infrastructure, but improve local roads and sidewalks for motorists, pedestrians and cyclists, ensuring mobility solutions that will help the surrounding communities continue to prosper.

The Walk Bridge Replacement

As a vital component to the busiest rail corridor in the nation, the existing Walk Bridge carries approximately 175 trains and 125,000 passengers per day. However, to enhance safety, reliability and ease of travel, the existing four-track structure is being completely replaced on the existing alignment with a new fixed-approached span and twin, 240-foot vertical-lift spans. With design services provided by HNTB, these spans will carry two tracks each and will have the ability to be operated individually in the event of a necessary track outage. In addition, the new Walk Bridge has been designed to be constructed with minimal disruption to marine navigation operations on the Norwalk River.

Prominent aesthetic features include decorative facades for the machinery room enclosures, arch designs within the tower framing, decorative railings on the exterior walkways, a three-story control house, and aesthetic lighting for the entire bridge. These design considerations were made with the involvement of local members of the Design Advisory Committee (DAC).

Location: Norwalk, CT

Client: Connecticut Department of Transportation