The Blue Star Turnpike begins near the Massachusetts state line in the town of Seabrook and travels north through Hampton and its neighboring municipalities.

Construction of the turnpike was approved in 1947 and began a year later in an effort to bypass congestion on U.S. Route 1 (US 1), the main seacoast highway.

[3][5] The northbound Hampton outlet is considered the state's flagship store, with annual sales of $33.5 million, and largely serves out-of-state customers.

[3][7] The New Hampshire section of the highway is 16 miles (26 km) long, the shortest of any state on I-95, which traverses the entire U.S. East Coast from Florida to Maine.

[10] The corridor is also served by several private intercity bus operators and public transit systems, including the Cooperative Alliance for Seacoast Transportation.

[11] During the summer months, the highway peaks at 125,000 daily vehicles and becomes routinely congested as weekend vacationers from the Greater Boston area travel to destinations in New Hampshire and Maine.

[13] Heavy congestion on US 1, particularly tourists from Massachusetts traveling to destinations in New Hampshire and Maine, led to proposals in the 1930s for a bypass that would connect with a new bridge over the Piscataqua River near Portsmouth.

[20][21] Several seacoast towns voiced their opposition, due to fears that traffic would bypass New Hampshire's beaches, and instead favored widening US 1.

[9][23] The state government formally approved the construction of the turnpike in February 1948, setting up a tollway commission to purchase and condemn land for right-of-way.

[24] Among the affected landowners was then-Governor Charles M. Dale, who opted to donate part of his North Hampton farm instead of accepting a payment from the state government.

[27][28] Early construction was slowed by a temporary injunction requested by the New Hampshire Gas and Electric Company to allow for the relocation of utility poles in the highway's right-of-way.

[29] State highway engineer Daniel Dickenson resigned from his position in August 1949, following an investigation ordered by governor Sherman Adams into the awarding of a design contract for the turnpike project.

[31] Amid the investigations, the state legislature approved an additional $280,000 in contingency funds (equivalent to $2.84 million in 2023)[17] that would also be used to expand an interchange on the existing US 1 Bypass.

[32][33] Major work on the toll road's main elements, including 14 overpasses, three bridges, and an 800-foot (240 m) traffic circle in Portsmouth, was mostly completed by December 1949.

[34] The turnpike had no services and was monitored by state police and highway workers, offering free vehicle towing and tire changes.

[50] A high-level, six-lane bridge over the Piscataqua River, connecting with extensions of I-95 through Portsmouth and Kittery, was proposed in the early 1960s to complete the missing link in the freeway.

[51] A competing plan to twin the existing Maine–New Hampshire Interstate Bridge was submitted by the Maine government, but was determined to be more costly due to land required for its approaches, which were already occupied by buildings.

[52] Following a four-year debate, the New Hampshire state legislature approved designs for the high-level bridge in early 1965 despite some opposition from Portsmouth residents.

[9] Plans for the new Piscataqua River Bridge had already included a wider approach, while the south end at the Massachusetts state line was rebuilt as an eight-lane highway in 1968.