Interstate 20 is a major eastâwest Interstate Highway in the Southern United States. Iâ20 runs 1,535 miles beginning near Kent, Texas, at Interstate 10 to Florence, South Carolina, at Interstate 95. Between Texas and South Carolina, Iâ20 runs through northern Louisiana, central Mississippi, western and north-central Alabama, and north-central Georgia. Iâ20 intersects seven of the 10 primary northâsouth Interstates and also the east-west Interstates 10 and 30.