Selected Alternatives
This project involves the reconstruction and widening of an approximate 3.5-mile section of the Spaulding Turnpike beginning at the north end of the Gosling Road Interchange (Exit 1) in the Town of Newington and continuing to approximately the Dover Toll Plaza, just north of Exit 6, in the City of Dover. The project also involves the replacement and widening of the Little Bay Bridges, rehabilitation of the General Sullivan Bridge, and the reconstruction / consolidation of the interchanges within the project area. The following sections provide a description of the various elements of the project:
Little Bay Bridges
- Rehabilitate/Widen the Little Bay Bridges (LBB) (nine-span 1,589' long structure) to eight lanes (three general purpose lanes plus an auxiliary lane in each direction) maintaining the existing easterly edge of the bridge and widening entirely to the west.
- Eight lanes on the bridges provides an adequate level of service (LOS D) for the projected travel demand in 2025.
- The existing profile of the Little Bay Bridges (suitable for 60 mph design criteria) will be maintained, as will the existing vertical clearance over the navigable channel.
- The bridge rehabilitation will involve replacing the existing bridge decks and evaluating the existing steel girders to determine if modification or replacement is required.
- Bridge construction will be completed in two phases with traffic maintained on the existing bridges while the proposed bridge widening is constructed and traffic shifted onto the widened section of the bridge while the existing bridges are rehabilitated.
General Sullivan Bridge
- The General Sullivan Bridge (GSB) superstructure will be removed and replaced with a new steel bridge to provide recreational access and connectivity between Newington and Dover, across Little Bay, for pedestrian and non-motorized use..
- The GSB is an historic landmark structure. It is the second highest rated historic bridge in the state, eligible for the National Register of Historic Places, and identified as a highly valued Section 4(f) resource.
- The GSB is currently an important bike/pedestrian connection across Little Bay and is used for fishing and other recreational activity. These transportation connections and recreational activities will be maintained on the GSB.
- The Selected Alternative will involve replacement of the historic GSB, which spans the navigational channel of Little Bay between Newington and Dover. The replacement bridge (identified as “Alternative 9” in the FSEIS/SROD) involves the complete removal and replacement of the GSB superstructure with a new steel bridge following the existing GSB alignment, thereby allowing the reuse of the existing GSB stone masonry piers.
Dover
- The design in Dover provides a full service interchange at Exit 6 and improves both system and local connectivity for the neighborhoods on both sides of the Turnpike and US 4, and for travelers heading easterly on US 4 towards Dover and northerly on the Turnpike.
- The three general purpose lanes plus an auxiliary lane in each direction (i.e., eight lanes in total) on the Turnpike will extend between Exits 3 and 6. Six lanes in total will extend south of Exit 3 to match into the exiting cross-section of the Turnpike at Exit 1 and will extend north through Exit 6 to the Dover toll plaza.
- The proposed two-lane northbound off-ramp provides dual left and right turn lanes at its intersection with US 4 to handle the heavy volume of traffic exiting the northbound Turnpike at Exit 6.
- The proposed bridge to carry US 4 over the Turnpike provides both eastbound and westbound traffic (replacing the existing westbound-only bridge).
- Signals at the northbound ramps and at the southbound on-ramp are proposed. A third signal at the Dover Point Road intersection to provide safe egress for the neighborhood is proposed.
- A bridge will be constructed to carry US 4 over the Spur Road Connector that is between Spur Road and Boston Harbor Road. This grade-separated facility provides a local connection for the neighborhoods north and south of US 4 and eliminates the need for a traffic signal at the Boston Harbor Road/US 4 intersection, where turns will be restricted to right turns in and out only. A short on-ramp from Spur Road Connector to the southbound on-ramp from US 4 maintains convenient access from the Dover Point neighborhoods and Hilton Park, while reducing some of the traffic demand at the Boston Harbor Road/US 4 intersection.
- The Exit 5 off- and on-ramps will be discontinued. The proximity of these ramps to the reconfigured Exit 6 creates traffic operational and safety problems. A section of Hilton Drive extending north from the existing ramps to the existing pump station will be retained to create a loop road for trucks to more easily exit the Wentworth Terrace neighborhood.
- An underpass, Hilton Drive, utilizing the existing traveled way beneath the Little Bay Bridges is proposed to connect the east and west sides of Hilton Park and the residential neighborhoods. The existing roadway would be widened to accommodate two-way travel at a design speed of 20 mph. The existing east-west pedestrian and bicycle connection at this location will be maintained.
- New sidewalks are proposed along the west side of Dover Point Road between Hilton Park and the existing sidewalk opposite the Division of Motor Vehicles (DMV) property; along the north side of Spur Road between the Bayview Park parking area and the Scammell Bridge; along the west side of the Spur Road Connector between Spur Road and Boston Harbor Road; along the new two-way Hilton Drive beneath the Little Bay Bridge; and along east side of Hilton Drive connecting to the reconstructed walkway along Pomeroy Cove.
- Retaining walls, ranging from 6 to 14 feet in height, are proposed along the west side of the Turnpike to reduce slope impacts on the properties between the Turnpike and Dover Point Road. Retaining walls, ranging from 4 to 18 feet in height, are proposed along the east side of the Turnpike to avoid impacts to Pomeroy Cove and to limit slope impacts on the properties in the Dover Point Road/Cote Drive neighborhood. The existing bicycle/pedestrian path abutting Pomeroy Cove and connecting Hilton Park and Wentworth Terrace to Dover Point Road will be maintained.
- Sound barriers are proposed on both the east and west sides of the Turnpike between the LBB and Exit 6 which will mitigate for the elevated noise levels. Sound barriers are also proposed on both the east and west sides of the Turnpike north of Exit 6 that extend north of the Dover Toll Plaza approximately 0.5 miles.
Newington
- The design in Newington provides a reconfigured full service interchange at Exit 3 (Woodbury Avenue) with northern access into the Pease Tradeport.
- The interchange at Exit 4 provides full access to Nimble Hill Road and Shattuck Way will remain.
- The three general purpose lanes plus an auxiliary lane in each direction (i.e., eight lanes in total) on the Turnpike will extend between Exits 3 and 6. Six lanes in total will extend south of Exit 3 to match into the exiting cross-section of the Turnpike at Exit 1 and will extend north through Exit 6 to the Dover toll plaza.
- Provisions for a future Railroad Spur over the Turnpike into the Pease Tradeport should the need arise. Right-of-way and easements will be procured as part of the project.
- Sidewalks are proposed on both sides of Woodbury Avenue between Fox Run Road and the northbound ramps at Exit 3. A sidewalk on the north side of the roadway will be extended through the interchange, across the Turnpike and onto Arboretum Drive heading south towards the Pease Tradeport.
- The Exxon-Mobil gas station/convenience store will continue to operate at its current location. However, access to the station from the Nimble Hill Road ramps will be limited to right-turns into and right-turns exiting from the existing driveway. A local roadway, which also provides access to the gas station, Thermo Electron, and one other parcel (with existing direct access to the Turnpike) is also proposed. This local roadway could also provide access to the former drive-in property via the roadbed of the existing southbound Turnpike should that property be developed in the future.
- The construction of the full access interchange at Exit 3 accommodates the Exit 2 northbound ramp traffic, thereby allowing these ramps to be discontinued and improve traffic operations.
- Woodbury Avenue would be reconstructed to extend the two existing lanes in each direction with a center-raised median from the Fox Run Road intersection through the Exit 3 interchange area. A reduced cross-section is proposed in front of the Isaac Dow house and Beane Farm property to minimize impacts to these two historic resources.
- Bridge work will include the construction of a 2 or 3-span structure to carry Woodbury Avenue over the Turnpike, and widening and rehabilitation of the structure carrying the Turnpike over Shattuck Way.
- Two signals are proposed, one each at the intersection of the northbound and southbound Exit 3 ramps with Woodbury Avenue.