[5] In 1977, LA 601 was truncated to its current terminus after I-20 was completed, cutting off the southern section of the route.

[7] The middle segment between I-20 exits 173 and 182, which comprised most of the route, was deleted from the state highway system around 2013.

It is a two-lane roadway that runs to the east of Richmond mostly paralleling a canal named Brushy Bayou.

Louisiana Highway 602-2 (LA 602-2) (0.935 miles or 1.505 kilometres) runs inside Mound between I-20's exit 182 and US 82.

Louisiana Highway 604 (LA 604) runs 9.22 miles (14.84 km) from St. Joseph to Lake Bruin.

Louisiana Highway 608 (LA 608) runs 21.77 miles (35.04 km) from Lake St. Joseph to Balmoral.

Louisiana Highway 611 (LA 611) is a collection of three current and ten former state-maintained streets in Jefferson, Metairie, and New Orleans.

Louisiana Highway 612 (LA 612) runs 3.60 miles (5.79 km) from Bossier City to Sligo.

[26] Louisiana Highway 616 (LA 616) runs 6.20 miles (9.98 km) from Claiborne to West Monroe.

It spanned 2.2 miles (3.5 km) in a west to east direction[30] along the shore of Lake Borgne near what is now known as Old Shell Beach.

[36] The route heads southeast from Yscloskey, running along the north bank of Bayou La Loutre.

After passing through Hopedale, LA 624 curves to the northeast with the bayou and proceeds 1.5 miles (2.4 km) to the end of state maintenance.

A local road continues a short distance to a dead end at the Mississippi River Gulf Outlet Canal.

Louisiana Highway 625 (LA 625) runs 0.25 miles (0.40 km) in an east–west direction along Maple Street in Yscloskey, St. Bernard Parish.

Louisiana Highway 627 (LA 627) runs 1.14 miles (1.83 km) in a north–south direction along Prospect Avenue in Norco, St. Charles Parish.

[45] The route connects US 61 (Airline Highway) with LA 48 (River Road) in an area known as Good Hope.

In the early 2000s, the southern portion of LA 627 was re-routed from Prospect Avenue onto a parallel road formerly known as Garrison Street.

Reaching the Upper Guide Levee of the Bonnet Carré Spillway, LA 628 turns away from the river and heads northeast on C.C.

Louisiana Highway 630 (LA 630) ran 0.94 miles (1.51 km) in a west–east direction along Courthouse Lane in Hahnville, St. Charles Parish.

[52] The route headed southwest from LA 18 (River Road), which runs along the Mississippi River, made a zigzag around the St. Charles Parish courthouse, and continued to the Texas & Pacific Railroad (now the Union Pacific Railroad) tracks.

The route has a spur that travels 0.5 miles (0.80 km) to a junction with US 90 in Des Allemands, providing access from the main highway to the small business district.

[54] The route heads southeast along Levee Road and crosses both LA 631 Spur (Old US 90) and current US 90 in Des Allemands.

Louisiana Highway 634 (LA 634) ran 0.25 miles (0.40 km) in a west–east direction along J.B. Green Road in Des Allemands, St. Charles Parish.

Louisiana Highway 635 (LA 635) runs 0.26 miles (0.42 km) in an east–west direction north of Des Allemands, St. Charles Parish.

[57] The route connects US 90 and its former alignment, LA 631 (Old Spanish Trail) between Des Allemands and Paradis.

[46] LA 635 was created in the 1955 Louisiana Highway renumbering[41] following a different connector road immediately to the north that no longer exists.

Its only major feature is the old Johnson (later renamed Carroll) Plantation, in which a few slave cabins and an overseer's house remain.

It travels 6.9 miles (11.1 km) in the shape of a capital J, starting northwest, veering northeast, and then turning north, serving the communities of Lutcher and Gramercy and providing a connection to Interstate 10 (I-10) for those towns.

[61] The route heads north from LA 44 at the east bank levee of the Mississippi River and crosses the Canadian National Railway (CN) tracks at grade.

After 1.3 miles (2.1 km), it turns to the south and ends at an intersection with LA 643, which continues in a general eastward direction to nearby Lac Des Allemands.