Interstate 393 is a spur taking traffic from I-93 and the capital city of Concord to points east along U.S. 4/202. These two routes continue to Portsmouth and Rochester, respectively. The freeway bypasses Concord Municipal Airport (CON) and the commercialized corridor along NH 9 (former U.S. 4/202) to the north.
The Federal Highway Administration (FHWA) approved the addition of the 3.5 mile long spur route in Concord to the Interstate System on October 31, 1974 under the provisions of 23 U.S.C. 103(e)(1). The designation of Interstate 393 was approved by the American Association of State Highway Officials (AASHTO) on July 13, 1976.
The freeway spur initially ran east from the preexisting cloverleaf interchange between I-93 and the U.S. 3-4-202 connector to NH 9 (Loudon Road) in August 1981.1 The route was proposed to extend east from Concord to the Spaulding Turnpike in 1983, but that extension was dropped in favor of upgrading New Hampshire Route 101 to a freeway between I-93 and I-95.2 That left construction of the eastern leg of I-393 beyond NH 106, which opened in December 1988.3