The shields of Louisiana's primary and auxiliary Interstate highways. There are eight primary Interstate highways and ten auxiliary Interstate highways in Louisiana. Interstate 10 (I-10) - Runs from the Texas state line on the Sabine River at Orange, TX to the Mississippi state line on the Pearl River east of Slidell, LA. Interstate 12 (I-12) - Runs from the Texas state line on the Sabine River in Deweyville, TX to I-10/59 in Slidell. Interstate 14 (I-14) - Runs from the Texas state line near Leesville, LA to the Mississippi state line near Natchez, MS. Interstate 20 (I-20) - Runs from the Texas state line west of Greenwood, LA to the Mississippi state line on the Mississippi River west of Vicksburg, MS. Interstate 49 (I-49) - Runs from I-10 in Broussard to the Arkansas state line north of Ida, LA. Interstate 55 (I-55) - Runs from the Mississippi state line north of Kentwood, LA to I-10 in Gretna after crossing the Crescent City Connection over the Mississippi River fr...