Route 6/10 Interchange

Reconstructing the Route 6/10 Interchange in Providence, Rhode Island, is the largest design-build project in the history of the Rhode Island Department of Transportation (RIDOT). This monumental $248 million initiative includes the replacement of 800 feet of raised highway and associated ramp structures, alongside lowering approximately 1,300 feet of the Providence Viaduct by as much as 40 feet to grade below local roadways. Nine bridges over highways and roadways are being replaced and constructed, culminating in a comprehensive redesign of the entire Route 6 and 10 Interchange. This transformative effort integrates missing ramp movements, strategically relocates other ramps to improve functionality, replaces drainage systems, and adds shared-use pedestrian and bicycle trails, complete with associated bridges.

CHA developed the interchange design that formed the project’s basis. The project required an environmental reevaluation according to National Environmental Policy Act (NEPA) requirements. CHA completed this work in parallel with the design development and the procurement process, resulting in the identification of the need to incorporate a new ramp, referred to as the “missing link.” CHA re-designed the interchange in short order to include the new fly-over ramp, which was readily accepted by the Federal Highway Administration (FHWA).

Subsequently, RIDOT retained CHA to provide engineering support during construction. However, the onset of the COVID pandemic precipitated a substantial delay in construction progress. CHA developed an innovative ramp detour plan for one of the bridges that eliminated staged construction, effectively reducing the construction schedule by one year to bring the project back on track. Through construction, CHA has served as owner’s representative, acting as an extension of RIDOT’s staff.

Project summary


This $248 million endeavor represents the single large design-build project in RIDOT's history.


Nine bridges over highways and railroads are being replaced and constructed.

1.3K ft.

About 1,300 feet of Providence Viaduct is being lowered by as much as 40 feet to grade.

Talk to an expert

Bob Talbot, PE*

Bob Talbot, PE*
Principal Engineer

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Bob brings 34 years of experience designing and managing civil, highway and interchange design projects, including over 20 years of project management for large multidisciplinary projects. Bob is experienced in all aspects of design, including horizontal and vertical geometry; drainage and hydraulics; traffic maintenance; railroad coordination (including Amtrak); construction management; and preparation of final contract plans, cost estimates, and specifications.