State Route 37 in central Rhode Island is a short but critical east-west freeway in the Providence metropolitan area, serving the cities of Cranston and Warwick, two of the state's most populated cities. The corridor includes major retail, office, and residential areas, and also links T.F. Green International Airport (located in Warwick) with Interstate 295. With a daily traffic count of over 42,000 vehicles, Route 37 is one of the state's busiest corridors.
Route 37 was built in the 1960s, and the freeway's bridges are deteriorating because of increasing vehicular volumes and freight demands. Almost half of its bridges are classified as being in poor condition. To alleviate these deficiencies and enhance Route 37's capabilities to meet future traffic demands, the Rhode Island Department of Transportation (RIDOT) is currently constructing an extensive, three-phased Route 37 Improvements Project to replace or rehabilitate numerous bridges, address safety and congestion issues, and reduce vehicle emissions along the corridor. The total cost of the project is $309.6 million.
The current second phase of this project began construction in 2022, and its completion is expected in 2026. Phase 2 includes Bridge Group 51B and the Cranston Canyon section of the route, said RIDOT Chief of Public Affairs Charles St. Martin.
“This second contract is rebuilding six bridges and building one new bridge along the Route 37 corridor west of Pontiac Avenue in Cranston,” St. Martin said. “This phase will also make a number of improvements to improve safety and reduce congestion at the interchange of Route 37 and I-295, and along I-295 itself in the section commonly known as 'Cranston Canyon' because of the rocky outcropping on this section of the interstate.”
Phase 2 is a design-build project, which was awarded to Aetna Bridge Company of Warwick, Rhode Island. The lead design firm is AECOM.
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According to St. Martin, the Phase 2 improvements include:
- Creating a third lane at I-295 North with new pavement and minor widening, which will work as an auxiliary lane from Route 37 heading north
- Extending this auxiliary lane northbound to the Route 6 interchange in Johnston
- Shifting the ramp from Route 37 East to I-295 North from the high-speed lane to the right lane, improving safety and reducing conflicting movements
- Repositioning the ramp from I-295 North to Route 37 West to eliminate a conflicting weave
- Widening the ramp from Route 37 West to I-295 North to improve sight lines and reduce crashes
Construction of Phase 1 (Bridge Group 51A) of the project began in 2020 and is expected to be completed by the end of this year. This phase includes preservation, major rehabilitation, and/or reconstruction of 15 bridge structures between U.S. Route 1 (Post Road) in Warwick and the Pontiac Avenue interchange in Cranston. Six of these bridges were deemed structurally deficient. Four of them are being replaced, and the other two are being rehabilitated. Phase 1 also includes safety improvements at the Pontiac Avenue interchange from Route 37 West, widening the highway and ramps to eliminate chronic congestion and improve safety.
Construction work also commenced in June 2025 on Phase 3, which encompasses Bridge Group 51C. This phase will replace and rehabilitate six bridges carrying Route 37 over local roads, arterials, and rail lines; remove two obsolete bridges; and “right-size” the highway corridor to ensure it meets Rhode Island’s current transportation needs.
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“Route 37 was overbuilt as part of a proposed highway expansion project that was never constructed,” St. Martin said. “Additionally, a new at-grade interchange at Route 37 and U.S. Route 1 [Post Road] will eliminate the overbuilt loop ramps, restore wetlands in the area, and open up land for future economic development. Pedestrian crossings on Route 1 and Route 2 [New London Avenue] will be enhanced, and traffic signals will be coordinated along both corridors. Phase 3 construction is projected to be complete in the summer of 2026.”
The Bridge Group 51B/Cranston Canyon Project is made possible by RhodeWorks, RIDOT's ongoing commitment to repair structurally deficient bridges and bring Rhode Island's transportation infrastructure into a state of good repair, promote economic development, and create jobs.
According to St. Martin, the Phase 2 project cost is $85 million total. RIDOT was awarded a $21 million BUILD grant, and the remaining project cost is 80 percent Federal Highway Administration funding and 20 percent state match.
The U.S. Department of Transportation's Better Utilizing Investments to Leverage Development (BUILD) grant program provides grants for surface transportation infrastructure projects with significant local or regional impact. The BUILD program — previously known as the Rebuilding American Infrastructure with Sustainability and Equity (RAISE) and Transportation Investment Generating Economic Recovery (TIGER) discretionary grants — was established under the American Recovery and Reinvestment Act of 2009 and operated under annual appropriations acts until authorized in November 2021.
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For Phase 1, the Route 37 Improvements Project had secured a $20 million TIGER grant. A $25 million RAISE grant was secured for Phase 3.
St. Martin said that work on the project is progressing on schedule.
“The Phase 2 bridge replacements are near completion and have punch list work items remaining,” he said. “The I-295 North highway widening is completed with only the final paving remaining. We are completing the bridge replacement punch list work items, and have started the remaining milling and paving of I-295 North, and installing new highway overhead signage, lighting, stormwater treatment areas, and improved drainage.”
Over a weekend at the end of July, there were lane and ramp closures at the I-295/Route 37 interchange in Cranston, during which construction was completed on a new flyover ramp to carry drivers from Route 37 East to I-295 North. This new ramp takes traffic over I-295 North. Drivers enter the highway on the right-hand side instead of the left-hand side, a more conventional design that will improve safety and reduce crashes.
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With the opening of the new flyover bridge, RIDOT also opened a new service road alongside I-295 North at the ramps for Route 37. This will provide more room for traffic entering and exiting the highway in a separate lane from I-295 through traffic.
The design-build process is aiding project construction by keeping traffic moving through the busy corridor with the least amount of disruption. It also allows design and construction activities to take place at the same time.
“One of the areas of competition [for the contract bidders] was to show us how they were going to mitigate the inconvenience during construction,” RIDOT Director Peter Alviti said. “They have worked out an ingenious plan to keep the traffic flowing during all phases of construction here. The temporary inconvenience of construction that people are bearing is going to mitigate future permanent inconveniences that would come with the closing of these bridges.”
“RIDOT used a weekend shutdown to replace a bridge using self-propelled modular transporters [SPMTs],” St. Martin added. “The bridge carries the Route 37 West on-ramp to I-295 North over Cranston Street. A different weekend closure was used to connect the new bridge ramp relocating the Route 37 Eastbound to I-295 North ramp. These strategies reduced the impact of traffic detours and demolition to a single weekend. I-295 North widening started in an earlier stage of construction to allow the ability to maintain the same number of lanes of traffic and be able to shift as needed.”
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In addition to the use of SPMTs to build and move a new bridge, other less common construction methods have been utilized on the Phase 2 work. Crews re-used the existing steel beams by cutting off the deteriorated beam ends on the bridge carrying Route 37 over Cranston Street. Geosynthetic reinforced soil (GRS) walls and abutments were used for three bridges, allowing the walls and abutments to be constructed prior to any bridge demolition and structure replacement. GRS walls are built with a soil-geosynthetic composite mass that functions as a reinforced block.
A precast arch bridge over bike paths was used to expedite the bridge replacement. The precast arch bridge was built under the existing steel beam bridge prior to that bridge being demolished. Route 37 roadway was then built on-grade over the precast arch bridge, eliminating the need to detour Route 37 traffic in this area.
- Owner: Rhode Island Department of Transportation
- General Contractor: Aetna Bridge Company, Warwick, Rhode Island
- Designer: AECOM, Providence, Rhode Island
- Owner’s Representative: Michael Baker International Inc., Providence, Rhode Island
- Owner's Representative, Phase 3: VHB Inc., Providence, Rhode Island
- Other Contractors: D’Ambra Construction Co. Inc., Coventry, Rhode Island; J.R. Vinagro Corporation, Johnston, Rhode Island Photos courtesy of Rhode Island Department of Transportation
