Louisiana State Route 55 ran 27.1 miles (43.6 km) in a north–south direction from the junction of US 79/US 80/State Route 4 in Shreveport, Caddo Parish to the Arkansas state line north of Ida.

Louisiana State Route 57 ran 38.9 miles (62.6 km) in a general north–south direction, existing as two disconnected sections.

Louisiana State Route 67 ran 16.1 miles (25.9 km) in a general east–west direction in two disconnected segments.

The western portion extended from State Route 15 at Foules, Catahoula Parish to a dead end at the Tensas River.

Louisiana State Route 71 ran in a west–east direction from Chipola to Clifton.

SR 71 formerly turned south and overlapped current LA 25 to Franklinton, but this was removed after 1937.

Louisiana State Route 81 ran 7.1 miles (11.4 km) in a south–north direction from Sea Breeze to Montegut.

[21] Louisiana State Route 86 ran 12.1 miles (19.5 km) in an east–west direction from St. Martinville to Catahoula.

Louisiana State Route 91 ran 20.3 miles (32.7 km) in a north–south direction from Norwood to Slaughter.

Louisiana State Route 98 ran 37.7 miles (60.7 km) in a general west–east direction from Holmwood to Lake Arthur.

In the original Louisiana Highway system in use between 1921 and 1955, the modern LA 14 was part of three separate routes.

The section from Lake Charles to Holmwood was a small part of State Route 42.

[25] Route 42 followed the modern US 171 corridor from Lake Charles as far north as Mansfield in DeSoto Parish.

Southeast of the Mermentau River bridge at Lake Arthur, the highway made a jog at LA 717 east onto Cypress Point Road then south onto Clesmae Road to rejoin the present alignment.

[28] On the east side of Gueydan, the highway turned south from Main Street onto 13th Street, then east onto Maree Michel Road, and south onto Hair Road to rejoin the current alignment.

[29][30] This portion of the route was re-aligned by the time of the 1955 Louisiana Highway renumbering.

[28] Sharp turns have been smoothed out over several portions of the route, most notably in Iberia Parish, where short segments of the original route bypassed during the 1920s are now local roads known as Old LA 25 Road.