Portsmouth is on Interstate 95, making it easily accessible by car from Boston (about an hour south) or Portland, Maine (about an hour north). Parking in the historic district is metered and limited in summer; the city operates a free parking garage on Hanover Street that is within easy walking distance of Market Square.
The Amtrak Downeaster runs between Boston North Station and Portland, Maine, with a stop at Durham (7 miles west of Portsmouth) and another at Wells, Maine. From Durham, a taxi or rideshare to Portsmouth is straightforward. Boston's South Station is also served by Greyhound and Concord Trailways buses, with direct services to Portsmouth's downtown bus terminal on Market Street.
Portsmouth International Airport at Pease, just north of the city, has limited scheduled service (primarily Spirit Airlines and some seasonal routes); most visitors arriving by air use Boston Logan, about 65 miles south.