then continues northeast through the towns of North Hampton and Greenland and crosses over several highways before reaching its next interchange. The turnpike enters the city of Portsmouth and intersects NH 33 near the city's international airport. After passing Portsmouth Regional Hospital, I-95 intersects the Spaulding Turnpike (US 4/NH 16) and U.S. Route 1 Bypass (US 1 Byp.) via ramps to the Portsmouth Circle. The freeway travels through the residential neighborhoods of western Portsmouth and intersects Market Street before crossing over the Piscataqua River Bridge into Maine, where it becomes the Maine Turnpike. The New Hampshire section of the highway is long, the shortest of any state on I-95, which traverses the entire U.S. East Coast from Florida to Maine. It is entirely located within Rockingham County and is generally eight lanes wide. The New Hampshire Department of Transportation, which maintains the highway through its Bureau of Turnpikes, measures traffic volumes at various points that are expressed in terms of annual average daily traffic. Traffic volumes on I-95 within the state in 2015 ranged from a minimum of 63,000 vehicles southwest of Portsmouth to a maximum of 98,000 vehicles near the Spaulding Turnpike. The corridor is also served by several private intercity bus operators and public transit systems, including the Cooperative Alliance for Seacoast Transportation. 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. History Predecessors The earliest roads traversing New Hampshire's Seacoast were constructed in the 17th century to connect Hampton to the Massachusetts Colony. They were later upgraded in the 18th century for stagecoach service and replaced by a toll road named "The Turnpike" that operated from 1810 to 1826. The toll road was purchased by the towns of Hampton and Hampton Falls in 1826 and renamed "Lafayette Road" for the Marquis de Lafayette in 1830. These roads were later acquired by the state government to form a modern highway system for automobiles and was assigned the designation of NH 1 in 1909. NH 1 was succeeded by US 1 in 1926, which was established as part of a national numbered highway system. The highway was paved from 1929 to 1931 and later upgraded with traffic signals to handle increased use. Heavy congestion on US 1, particularly tourists from Massachusetts traveling to destinations in New Hampshire