List of Interstate Highways in Louisiana

The Interstate Highway System in Louisiana consists of 933.84 miles (1,502.87 km)^[1] of freeways constructed and maintained by the Louisiana Department of Transportation and Development (La DOTD).

Interstate Highways of the Louisiana Highway System
Highway markers in use for primary interstates (left) and auxiliary interstates (right)
Interstate Highways highlighted in red
System information
Length	933.84 mi[1] (1,502.87 km)
Formed	June 29, 1956 (authorized);[2] February 24, 1960 (opened);[3] April 23, 1960 (signed)[4]
Highway names
Interstates	Interstate X (I-X)
System links
Louisiana State Highway System Interstate US State Scenic

The system was authorized on June 29, 1956 when President Dwight D. Eisenhower signed into law the Federal Aid Highway Act of 1956.^[2] The Louisiana Department of Highways, predecessor of the DOTD, began construction shortly afterward on its portion of the system, to which approximately 686 miles (1,104 km) was initially allotted.^[5] The first road segment in the new system was officially opened and dedicated on February 24, 1960 and consisted of a portion of the Pontchartrain Expressway (I-10) in New Orleans.^[3] Two months later, the first Interstate Highway shields installed in Louisiana accompanied the opening of a portion of I-20 near Ruston on April 23.^[4]

Primary interstates

Number	Length (mi)[1]	Length (km)	Southern or western terminus	Northern or eastern terminus	Formed	Removed	Notes
I-10	274.42	441.64	Texas state line at Orange, TX	Mississippi state line east of Slidell	01960-01-011960[3]	current	Southern Louisiana's primary east–west route serving Lake Charles, Lafayette, Baton Rouge, New Orleans, and Slidell
I-12	85.59	137.74	I-10 in Baton Rouge	I-10/I-59 in Slidell	01967-01-011967[6]	current	Northern bypass of New Orleans metropolitan area via Hammond
I-14	—	—	Texas state line near Leesville, LA (undecided)	Mississippi state line near Natchez, MS (undecided)	proposed	—	Proposed extension roughly paralleling the LA 28 corridor
I-20	189.87	305.57	Texas state line west of Greenwood	Mississippi state line at Vicksburg, MS	01960-01-011960[4]	current	Northern Louisiana's primary east–west route serving Shreveport and Monroe
I-49	239.25	385.04	I-10/US 167 in Lafayette	Arkansas state line north of Ida	01983-01-011983[7]	current	Louisiana's primary north–south route, connecting I-10 and I-20 via Alexandria; final gap in Shreveport is under construction and southern extension from Lafayette to New Orleans is planned
I-55	65.81	105.91	I-10/US 51 in LaPlace	Mississippi state line north of Kentwood	01960-01-011960[8]	current	North–south route in southeastern Louisiana via Hammond
I-59	11.48	18.48	I-10/I-12 in Slidell	Mississippi state line north of Pearl River	01962-01-011962[9]	current	North–south route in southeastern Louisiana via Slidell
I-69	—	—	Texas state line southwest of Shreveport (undecided)	Arkansas state line northeast of Haynesville (undecided)	proposed	—	Proposed extension roughly paralleling the US 79 corridor
Former       Proposed and unbuilt

Auxiliary interstates

Number	Length (mi)[1]	Length (km)	Southern or western terminus	Northern or eastern terminus	Formed	Removed	Notes
I-110	8.89	14.31	I-10 in Baton Rouge	US 61 in Baton Rouge	01964-01-011964[10]	current	Baton Rouge spur; formerly designated as I-410
I-210	12.40	19.96	I-10 west of Lake Charles	I-10 east of Lake Charles	01964-01-011964[11]	current	Lake Charles downtown bypass
I-220	17.62	28.36	I-20/LA 3132 in Shreveport	I-20 in Bossier City	01977-01-011977[12]	current	Shreveport–Bossier City downtown bypass
I-310	11.25	18.11	US 90/LA 3127 in Boutte	I-10 west of Kenner	01983-01-011983[13]	current	Spur west of New Orleans
I-310	2.70	4.35	US 90 Bus. in New Orleans	I-10 in New Orleans	01964-01-011964[14]	01969-01-011969[15]	Cancelled Vieux Carré Riverfront Expressway
I-410	1.90	3.06	LA 67 in Baton Rouge	I-10 in Baton Rouge	01961-01-011961[16]	01964-01-011964[10]	Unfinished Baton Rouge loop partially retained as I-110; planned as 13.60-mile (21.89 km) route with western terminus at I-10 near Port Allen[11]
I-410	48.5	78.1	I-10 west of New Orleans	I-10 in Eastern New Orleans	01969-01-011969[15]	01977-01-011977[17]	Cancelled southern bypass of New Orleans known as the Dixie Freeway; partially built as current I-310 and I-510
I-420	10.20	16.42	I-20 in West Monroe	I-20 in Monroe	01957-01-011957[18]	01964-01-011964[14]	Cancelled two-lane bypass of Monroe
I-510	3.04	4.89	LA 47 in New Orleans	I-10/LA 47 in New Orleans	01992-01-011992[19]	current	Spur in Eastern New Orleans
I-610	4.52	7.27	I-10 in New Orleans		01965-01-011965[20]	current	New Orleans downtown bypass
I-910	9.70	15.61	US 90 Bus. in Marrero	I-10/US 90 Bus. in New Orleans	01999-01-011999[21]	current	FHWA designation (not used by La DOTD) for freeway portion of US 90 Bus. and placeholder for future I-49 corridor
Former

See also

• United States portal
• U.S. Roads portal