Route 403, also known as the Quonset Freeway, is a numbered state highway located in Washington County and Kent County, Rhode Island, United States. The route is a nominally east–west limited-access freeway for its entire length. A spur of Rhode Island Route 4, Route 403 serves Davisville and Quonset Point, providing freeway access to Interstate 95 and the northern Providence metropolitan area from the industrial zone. The western terminus of the freeway is at a trumpet interchange with Route 4 in East Greenwich. The route has three unnumbered interchanges along its length, including a junction with U.S. Route 1 in North Kingstown, before terminating at an at-grade intersection with Roger Williams Way and Commerce Park Road in Quonset. Route 403 is the highest numbered route in Rhode Island.
Prior to 2006, Route 403 was a narrow, two-lane road through Davisville. The western terminus of the route was at an interchange with Route 4 and Rhode Island Route 402 in East Greenwich, and the eastern terminus was at U.S. Route 1 in North Kingstown. In order to accommodate increasingly heavy commercial and commuter traffic to and from the Quonset Business Park, the Rhode Island Department of Transportation constructed the Quonset Freeway as an upgraded Route 403. The relocation of the route began in 2000 and was constructed in two phases; Phase 1, a freeway from Quonset to Davisville, opened in June 2006. Phase 2 of the relocation project, which connected the freeway with Route 4, was completed one year ahead of schedule in December 2008.
Route description
Original Route 403
thumb|right|alt=Ground-level view of a divided four-lane freeway; directly in front a large, curved bridge crosses over the freeway.|The Quonset Freeway passing under Devil's Foot Road, the original Route 403, in Davisville
Prior to 2006, Route 403 was a narrow, two-lane road running for through Davisville, Rhode Island.
Route 403's original western terminus was at a complex interchange with Routes 4 and 402 in East Greenwich. Both Routes 402 and 403 were accessible from Exit 7 on Route 4 southbound; there was no access to either route from the northbound lanes of Route 4. After the Exit 7 ramp, Route 403 eastbound crossed over Route 4 and began to head in southeastern direction along Davisville Road. Shortly after its western terminus, Route 403 crossed the Hunt River into Washington County and Davisville, a village in the town of North Kingstown. After intersecting Old Baptist Road, a local route that connects to Route 102, Route 403 began to follow Devil's Foot Road, continuing on its southeastern trajectory.
Quonset Freeway
thumb|left|alt=Ground-level view of a divided freeway at a curve in the road; a green exit sign and a white bridge are visible in the distance.|The Quonset Freeway approaching the West Davisville Road overpass
The Quonset Freeway begins in East Greenwich at Exit 7 of Route 4; southbound, the exit is numbered 7B, as Exit 7A serves Route 402. Unlike Route 402, which is accessible only via Route 4 southbound, Route 403 is accessible from the northbound lanes of Route 4 via the newly constructed Exit 7. Shortly after the overpass, Route 403 turns to head almost due east. The freeway has its first interchange with West Davisville Road; the exit is accessible only from eastbound Route 403, and serves the villages of Davisville and Quidnessett. Closely paralleling Devil's Foot Road, Route 403 continues eastward before interchanging with U.S. Route 1 (Post Road) and Davisville Road; the two roads are served via a single exit. Westbound Route 403 has no direct interchange with either US 1 or Davisville Road; the route's first westbound exit in Quonset is signed as "To US 1," and connects to Post Road via Gate Road, a commercial outlet in Quonset.
By the 1980s, more than 12,000 cars were using Route 403 daily to access the business park; the Rhode Island Department of Transportation (RIDOT) estimated that this vehicle volume would exceed 25,000 by 2005.
Construction of the Quonset Freeway
left|thumb|alt=Overview map of a road intersection; Route 403 east has off-ramps that connect to US 1 and Davisville Road and is accessible from a US 1 on-ramp. Route 403 west has one off-ramp that connects to Gate Road and is accessible from Davisville Road. Route 403 terminates at Roger Williams Way.|Diagram of the eastern terminus of Route 403 in North Kingstown
Construction of "Phase 1" of the four-lane, limited-access Quonset Freeway began in 2000 with excavation of the route and right-of-way acquisition; the project required the demolition of 13 structures, five commercial and eight residential. Phase 1 included an extension of the highway into the Quonset Business Park and the construction of several overpasses in Quonset, an exit ramp to Gate Road, a full interchange with U.S. Route 1 in North Kingstown, and a partial diamond interchange with West Davisville Road in Davisville.
thumb|right|alt=Ground-level view of a freeway; a large, green sign marked with "Exit 7" is posted directly overhead. Two large bridges are visible in the distance.|The new Exit 7 off Route 4 north
Construction of the $100 million-Phase 2 of the Quonset Freeway began in 2004 and continued until 2008. The project included the construction of new bridges over the Northeast Corridor rail line, Route 402, and Route 4. The existing Route 403 bridge over Route 4 was also demolished as a part of Phase 2. The freeway and ramps from Route 403 west to Route 4 north and from Route 4 south to Route 403 east opened on October 23, 2008.
Exit list
Exits were numbered in fall 2018 as part of a statewide conversion to mileage-based exit numbers.