There are nine interstate highways within the state of Mississippi. This includes six primary interstates and three auxiliary interstates. The longest interstate is I-55, and the shortest interstate is I-110.
State highways in Mississippi have different numbering schemes. The primary highways are numbered from 1-76, and most three-digit numbered routes are numbered by region (300s in the northernmost part of the state, 600 in the southernmost). Three-digit numbered routes from 700s to 900s are usually short connectors and spurs.
In 1928, Mississippi Governor Theodore G. Bilbo appointed Horace Stansel head of a committee to investigate the state's highway needs. Stansel submitted an act to create a state highway system to the state legislature in 1930. Since then, Mississippi has gradually expanded its highway system.
Until 1987, there were but two major four-lane highways in Mississippi, not counting the Interstates, which were built during the 1960s and 1970s: U.S. Highway 49 (US 49) from Yazoo City to Gulfport and US 82 between Greenville and Winona. Things changed when the state legislature launched the $1.3 billion Four-Lane Highway Program of 1987.[2] This program gradually allowed for the funding of over 1,000 miles (1,600 km) of four-lane highway statewide. In 2002, the Four-Lane Highway Program was expanded in what was known as Vision 21.
MDOT was not created until 1992; this organization consolidated several services that already existed.
