Interstate 12

Interstate 12
Republic of West Florida Parkway
Route information
Maintained by LaDOTD
Length:	85.59 mi (137.74 km)
Existed:	October 17, 1957 – present
Major junctions
West end:	I-10 in Baton Rouge
	US 61 in Baton Rouge I-55 near Hammond LA 445 south of Robert LA 1077 near Goodbee LA 21 near Madisonville US 190 between Covington and Mandeville
East end:	I-10 / I-59 near Slidell
Highway system
Main route of the Interstate Highway System Main • Auxiliary • Business Highways in Louisiana ← LA 11 LA 12 →

Interstate 12 (I-12) is an intrastate Interstate Highway located entirely within the state of Louisiana. I-12 starts in Baton Rouge at Interstate 10, and travels along the North Shore of Lake Pontchartrain before ending at the intersection of Interstate 10 and Interstate 59 near Slidell. I-12 is only 85 miles long between Baton Rouge and Slidell, while I-10 takes 108 miles to travel between the same two points, so I-12 is heavily-used as a shortcut for through traffic on I-10. I-12 is six lanes from its western terminus until Exit 7 (O'Neal Lane) at which point it becomes a four-lane highway to its eastern terminus.

In 1993, the state legislature renamed Interstate 12 as the Republic of West Florida Parkway. In 2003, signs identifying the highway's official name and bearing the flag of the Republic of West Florida were erected by the Louisiana Department of Transportation and Development in order to highlight the unique history of Louisiana's Florida Parishes.

The highway is relatively short for a mainline route at only 85 miles (137 km). While Interstates 19, 66, 97, and the partially completed Interstate 99 are all shorter, none of these has two termini with the same route, much less within the same state (I-99 will eventually extend into New York). Compare the length of I-12 to that of the 73.5-mile (118.3 km) I-295 in New Jersey and Delaware, or the 72.8-mile (117.2 km) I-405 in California, or even the 121-mile (195 km) I-495 in Massachusetts, all of which are auxiliary Interstate Highways.

Route description

I-12's eastbound exit to LA 1249, which leads to the communities of Baptist and Pumpkin Center

At the bottom of I-12's eastbound ramp to LA 59, travelers also find a shield for the unrelated I-59, some 20 miles farther east

I-12 begins just east of downtown Baton Rouge at an interchange with I-10, with I-10 heading toward New Orleans and I-12 acting as a de-facto bypass of the New Orleans area. I-12 continues east passing through the suburbs of Baton Rouge, before transitioning into a rural interstate for the rest of its length. It makes an interchange with I-55 near Hammond. East of Hammond, the route passes near the northern shore of Lake Pontchartrain, and crosses scenic streams like the Tangipahoa River south of Robert, Sims Creek southeast of Goodbee, and the Tchefuncte River north of Madisonville. I-12 ends at I-10 and the southern terminus of I-59 near Slidell.

I-12 is the only Interstate roadway that Livingston Parish uses, as it virtually slices the parish in half.

History

Interstate 12 was added to the highway system on October 17, 1957, with I-12 running from I-10 in Baton Rouge to I-59 north of Slidell. By the mid-1960s, the routes had been realigned to their current configuration, with I-12 and I-59 both ending at I-10 near Slidell.

With major damage to the I-10 Twin Span Bridge across Lake Pontchartrain from Hurricane Katrina, I-12 was temporarily functioning as I-10. On October 14, 2005, the eastbound span of I-10 over Lake Pontchartrain was reopened to two-way traffic. The westbound span of I-10 reopened on January 6, 2006, with speed, weight and size restrictions, relieving I-12 of much of the congestion that was clogging it from the Lake Pontchartrain Causeway to the junction with I-10 and I-59.

Widening and Improvements

In 2009, a project broke ground to widen I-12 from the O'Neal Lane Interchange (exit 7) to the LA 447 interchange in Walker, Louisiana. The current bottleneck has traffic backed up for a few miles.

Also, in 2010, construction began at the Louisiana Highway 1088 overpass in St. Tammany Parish to make it an exit. The finished project has a widened LA 1088 over I-12. This exit was created to alleviate congestion on local roads and to create a more direct route to the newly opened Lakeshore High School.

In 2011, officials began constructing a third travel lane in each direction on I-12 from the Vincent's Bayou Bridge to the I-10/I-12/I-59 split.

Exit list

Parish	Location	#	Destinations	Notes
East Baton Rouge	Baton Rouge		I-10 west – Baton Rouge
		1A	I-10 east – New Orleans
		1B	LA 3064 (Essen Lane) to LA 73 (Jefferson Highway)	No westbound exit
			LA 1068 (Drusilla Lane) to LA 73 (Jefferson Highway)	Westbound exit and eastbound entrance only
		2	US 61 (Airline Highway)	Alternate route to Baton Rouge Metropolitan Airport Signed as exit 2A (south) and 2B (north)
		4	Sherwood Forest Boulevard
		6	Millerville Road
		7	LA 3245 (O'Neal Lane)
Livingston	Denham Springs	10	LA 3002 – Denham Springs
		12	LA 1026 (Juban Road)
	Walker	15	LA 447 – Port Vincent, Walker
		19	Colyell, Satsuma
	Livingston	22	LA 63 – Frost, Livingston
		29	LA 441 – Holden
		32	LA 43 – Springfield, Albany
Tangipahoa		35	LA 1249, Pumpkin Center Road, Baptist
		38	I-55 – New Orleans, Jackson	Signed as exits 38A (south) and 38B (north)
	Hammond	40	US 51 Bus. – Ponchatoula, Hammond	To Southeastern Louisiana University
		43	LA 3158 (Airport Road)
		47	LA 445 – Robert
St. Tammany		57	LA 1077 – Goodbee
		59	LA 21 – Madisonville, Covington
		60	Pinnacle Parkway, East Brewster Road
		63	US 190 – Mandeville, Covington	Signed as exits 63A (Southbound to Mandeville & Lake Pontchartrain Causeway) and 63B (Northbound to Covington)
		65	LA 59 – Mandeville, Abita Springs
		68	LA 1088 – Mandeville
		74	LA 434 – Lacombe, St. Tammany
	Slidell	80	Northshore Boulevard, Airport Road
		83	US 11 – Slidell, Pearl River
		85A	I-10 west – New Orleans
		85B	I-59 north - Hattiesburg
		85C	I-10 east - Bay St. Louis