Since 1993 regional airline service has operated at the Pease International Tradeport. Pan American Airways operates to and from Sanford, Florida and Gary, Indiana. Air travelers can also use facilities at Logan International Airport, one hour to Portsmouth's south in Boston, Massachusetts; at Portland International Airport, one hour to the north in Portland, Maine; or Manchester Airport in Manchester, New Hampshire, which connects the southern part of the state to Washington, New York, Chicago, Philadelphia, and Pittsburgh. Frequent daily limousine service is available between Logan and Portsmouth.
Bus transportation to Portsmouth is available on C&J Trailways, which also serves Logan airport. C & J's Portsmouth stop is at the Park and Ride bus terminal at Pease International Tradeport. Ferries are available between Portsmouth and Kittery, Maine. Passenger rail extends from Boston to Newburyport, Massachusetts. Service is also available within the state to Dover and Durham.
Interstate 95 is a direct link connecting Portsmouth with Portland, Maine, and Boston; it extends as far north as the Canadian provinces and south to Key West, Florida. The Spaulding Turnpike (Rte. 16) connects the city to Dover, Rochester, and further north to the White Mountains. U.S. Route 101 stretches west through Manchester and eventually to Keene, New Hampshire. U.S. Route 4 leads into the city from Concord to east. All roads are passable year-round to the experienced traveler.
Portsmouth, which grew inland from the banks of the Piscataqua River, developed around a series of narrow, winding, often one-way streets in the downtown area. The main thoroughfares converge at Market Square in the center of downtown Portsmouth. Memorial Bridge connects Portsmouth with Kittery, Maine. Other traffic can use I-95 and the U.S. Route 1 Bypass, both with bridges across the river. Other bridges in the city cross South Mill Pond and provide a link with Pierce Island.
Traffic in the city blossoms during the summer tourist season when the city's population doubles. Bridge traffic is especially heavy during these months. Cooperative Alliance for Seacoast Transportation (COAST), the regional transit line since 1981, provides bus service to the combined metropolitan area of Portsmouth, Rochester, Dover, Somersworth, and Durham. Walking the brick-paved streets and taking the downtown trolley during the summer are the best ways to get to know Portsmouth, and horse-drawn carriages are available.