Louisiana Highway 640 is a state highway

State highway

State highway, state road or state route can refer to one of three related concepts, two of them related to a state or provincial government in a country that is divided into states or provinces :#A...

 in Louisiana

Louisiana

Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...

 that serves St. John the Baptist Parish

St. John the Baptist Parish, Louisiana

St. John the Baptist Parish is a parish located in the U.S. state of Louisiana.The parish seat is Edgard, an unincorporated area and the unofficial parish captial is LaPlace, an unincorporated area. St. John the Baptist is one of the original 19 parishes in Louisiana. In 2010, its population was...

. It spans 2.2 miles (3.5 km) in a south to north direction.

Route description

From the south, LA 640 begins at an intersection with LA 3127 south of Edgard

Edgard, Louisiana

Edgard is a census-designated place in and the parish seat of St. John the Baptist Parish, Louisiana, United States. The population was 2,637 at the 2000 census. It is part of the New Orleans–Metairie–Kenner Metropolitan Statistical Area...

 and just west of West St. John High School. It heads north toward the Mississippi River

Mississippi River

The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

 where it meets LA 18. A few feet to the left of this intersection (in front of the St. John the Baptist Parish Courthouse), LA 640 crosses the river via the Edgard-Reserve Ferry

Edgard-Reserve Ferry

The Reserve-Edgard Ferry is a ferry across the Mississippi River in the U.S. state of Louisiana, connecting Reserve and Edgard.-External links:*Louisiana Department of Transportation and Development,...

. The highway ends at the landing on the east bank side at an intersection with LA 44 and LA 53.

With the exception of the ferried portion, is an undivided, two-lane highway for its entire length.

Junction list

Parish	Location	Mile	Junction	Notes
St. John the Baptist St. John the Baptist Parish, Louisiana St. John the Baptist Parish is a parish located in the U.S. state of Louisiana.The parish seat is Edgard, an unincorporated area and the unofficial parish captial is LaPlace, an unincorporated area. St. John the Baptist is one of the original 19 parishes in Louisiana. In 2010, its population was...	Edgard Edgard, Louisiana Edgard is a census-designated place in and the parish seat of St. John the Baptist Parish, Louisiana, United States. The population was 2,637 at the 2000 census. It is part of the New Orleans–Metairie–Kenner Metropolitan Statistical Area...	Southern terminus of LA 640
		0.00	LA 3127 Louisiana Highway 3127 Louisiana Highway 3127 is a state highway in Louisiana that serves Ascension, St. James, St. John the Baptist, and St. Charles Parishes. It spans in a northwest to southeast direction. It parallels LA 18 along the west bank of the Mississippi River, providing a much shorter inland bypass of...
		2.1	LA 18 Louisiana Highway 18 Louisiana Highway 18 is a state highway in Louisiana that serves Ascension, St. James, St. John the Baptist, St. Charles, and Jefferson Parishes. Called the Great River Road, it runs from west to east, parallel to the west bank of the Mississippi River, running from Donaldsonville to Gretna. It...  (River Road)	LA 18 departs to the east
		Begin concurrency
		2.15	LA 18 Louisiana Highway 18 Louisiana Highway 18 is a state highway in Louisiana that serves Ascension, St. James, St. John the Baptist, St. Charles, and Jefferson Parishes. Called the Great River Road, it runs from west to east, parallel to the west bank of the Mississippi River, running from Donaldsonville to Gretna. It...  (River Road)	LA 18 departs to the west
		End concurrency
		Edgard-Reserve Ferry Edgard-Reserve Ferry The Reserve-Edgard Ferry is a ferry across the Mississippi River in the U.S. state of Louisiana, connecting Reserve and Edgard.-External links:*Louisiana Department of Transportation and Development,...  over the Mississippi River Mississippi River The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...
	Reserve Reserve, Louisiana Reserve is a census-designated place in St. John the Baptist Parish, Louisiana, United States, on the east bank of the Mississippi River. The population was 9,111 at the 2000 census...	2.20	LA 44 (River Road/Jefferson Highway to the east and west) LA 53 Louisiana Highway 53 Louisiana Highway 53 is a state highway in Louisiana that serves St. John the Baptist Parish. It spans in a south to north direction and is known locally as Central Avenue.-Route description:... (Central Avenue to the north)	Southern terminus of LA 53
		Northern terminus of LA 640