Although MassDOT inventories Route 3 and US 3 as one continuous route, this table includes the mileage only for US 3 starting from its southern terminus in Cambridge. Special routes US 3 has one existing special route, a business route through Laconia, New Hampshire. Four other special routes may have existed in the past: an alternate and business route between Tyngsborough, Massachusetts, and Concord, New Hampshire, and bypass routes around Concord and Nashua, New Hampshire. Tyngsborough–Concord alternate route Tyngsborough–Concord business route Concord bypass route Nashua bypass route Laconia business loop U.S. Route 3 Business (US 3 Bus.) is a signed business route running north–south through downtown Laconia, New Hampshire. It runs from US 3 and NH 11 in Belmont north to US 3 in Laconia, along NH 107 and NH 11A. It is a former alignment of US 3, used before the Laconia–Gilford bypass was built. See also References External links US 3/Northwest Expressway on Bostonroads.com Photos of US 3 in New Hampshire Endpoints of U.S. Highway 3 03 03 03 Transportation in Middlesex County, Massachusetts Transportation in Hillsborough County, New Hampshire Transportation in Merrimack County, New Hampshire Transportation in Belknap County, New Hampshire Transportation in Grafton County, New Hampshire Transportation in Coös County, New Hampshire