Interstate-Guide Home State by State Interstate list Main Interstate Routes Hidden Interstates Decommissioned Interstates Future Interstates Business Loops & Spurs Interstates Facts & Trivia FWHA Rouge Log Kurumi's 3di Log

Interstate 12


Interstate 12 functions as a bypass route for Interstate 10 north of Lake Pontchartrain and the New Orleans metropolitan area. Although an intrastate route, the freeway provides a significant role in cross-country travel.

The freeway splits with Interstate 10 in Baton Rouge as a busy commuter route through suburban areas east to Denham Springs. Continuing east, I-12 becomes more rural through areas of pine forest, but still with moderate traffic given it accommodates just four overall lanes.

Interstate 55 crosses paths with Interstate 12 outside Hammond, the largest city between Baton Rouge and Slidell. The freeway passes south of the city street grid and quickly exits the area toward Covington and the Lake Pontchartrain North Shore communities of Madisonville and Mandeville. There U.S. 190 ties in from the north end of Lake Pontchartrain Causeway, a lengthy toll bridge leading south to Metairie and Jefferson Parish west of New Orleans.

The remainder of Interstate 12 leads east through St. Tammany Parish to Slidell and the junction with Interstate 10 and 59 north. The freeway passes through North Slidell and suburban areas before defaulting onto I-10 east across Pearl River Wildlife Management Area into Mississippi.

Parallel U.S. Routes

Interstate 12 replaced U.S. 190 as the through route north of Lake Pontchartrain. U.S. 190 parallels I-12 to the north from Baton Rouge east to Covington and to the south between Mandeville and Slidell.

Future Aspirations

According to the journal Roads and Bridges, the I-12 corridor should be extended westward. They describe it as follows: "Interstate 12 Houston to Austin: These metropolitan areas have grown rapidly. Less than 100 miles, this route would require upgrading from Austin to Interstate 10 along the state route 71 corridor." SH 71 is a four-lane roadway for its entire length, with portions already upgraded to expressway standard.

One upgrade along the SH 71 corridor is the SH 71 Express Project in Austin. Construction between early 2015 and late 2016 upgrades 3.9-miles of the highway, from Presidential Boulevard at AUS Airport to SH 130 near Onion Creek, to a limited access toll road. Work will add two new toll lane overpasses at FM 973 and SH 130.


Interstate 12 was completed between U.S. 61 (Airline Highway) at Baton Rouge and Interstate 55 at Hammond in 1969. The western most two miles of Interstate 12 opened in conjunction with Interstate 10 east from College Drive in 1965.2 Interstate 10 southeast from I-12 would not be completed until 1974, resulting in traffic defaulting from I-10 east onto I-12 and U.S. 61 until 1969.

In 1993, the Louisiana State Legislature passed a resolution declaring Interstate 12 the West Florida Republic Parkway. This name stems from the 74 day West Florida Republic existence that occurred between an 1810 revolt against Spain and the forced annexation of the eight parishes into the Louisiana Purchase by the United States. During mid-November of 2003, signs were installed proclaiming the highway the West Florida Republic Parkway.1

Highway Guides

Western Terminus - Interstate 10 - Baton Rouge, Louisiana
Perspective from Interstate 12 west
Westbound Interstate 12 at Exit 1B (Louisiana 1068), approaching Exit 1A (Interstate 10). This is the last exit before the end of Interstate 12 in Louisiana. Photo taken 08/12/02.
Westbound Interstate 12 approaching Junction Interstate 10. There are no END Interstate 12 signs or shield assemblies along westbound. Photo taken 08/12/02.
Westbound Interstate 12 at exit for eastbound Interstate 10 toward New Orleans. Interstate 12 traffic will merge with Interstate 10 westbound straight ahead. This marks the western terminus of Interstate 12. Photo taken 08/12/02.
This photo shows the same sign bridge several years earlier along westbound Interstate 12 at its terminus with Interstate 10. Interstate 10 proceeds westward towards downtown Baton Rouge. Vidcap taken 01/96.
The overhead ramp ahead is the eastbound Interstate 10 traffic crossing over westbound Interstate 12 traffic. The merge with Interstate 10 westbound is just beyond this overpass. Photo taken 08/12/02.
Westbound Interstate 12 traffic follows this transition ramp onto Interstate 10. Note the signage for the next exit uses the exit numbering system for Interstate 10. Photo taken 08/12/02.
Traffic from westbound Interstate 12 merges from the right onto westbound Interstate 10 in Baton Rouge. Photo taken 08/12/02.
Perspective from Interstate 10 east
Interstate 10 eastbound at Exit 158/College Drive. This roadway is named as such not for Louisiana State University, but for Baton Rouge Community College. The split with Interstate 12 eastbound is situated in 1.50 miles. Photo taken by Eric Stuve (12/17/02).
Graphical overhead on Interstate 10 eastbound for the pending split with Interstate 12. Interstate 12 is an 85 mile alternate route of Interstate 10 for traffic wishing to bypass the New Orleans metropolitan area. Because of this, one more lane is allocated for Interstate 12 over Interstate 10. The city of New Orleans is still 71 miles away at this point. Photo taken by Eric Stuve (12/17/02).
Summertime view of the 0.75 mile guide sign of Exit 158 Pictured above. Note the aforementioned sound wall construction. Interstate 10 exits the Baton Rouge metropolitan area by Exit 166/Louisiana 42 and 427. Photo taken 08/12/02.
Interstate 10 expands to four eastbound lanes in anticipation of the Interstate 12 beginning, one half mile to the east. The control city of Hammond is 40 miles to the east at this point, and the midpoint of Interstate 12 at Interstate 55. New sound barriers saw installation during 2002. Photo taken by Eric Stuve (12/17/02).
A closer view of the Interstate 10/12 panel Pictured above. A sign replacement project was underway during the Spring of 2000 that saw the replacement of all Interstate 10/12 interchange related signage. Photo taken by Jeff Royston (05/27/00).
The predecessor to the guide panel in the above photograph displayed only two lanes for Interstate 12 as opposed to the expanded three that now serves the Interstate beginning. Vidcap taken 01/16/96.
Interstate 12 begins as Interstate 10 turns southeastward toward Gonzales, La Place, and New Orleans. Development of Baton Rouge continues along the Interstate 12 corridor through to Exit 10/Louisiana 3002 at Denham Springs. Photo taken by Eric Stuve (12/17/02).
The first eastbound Interstate 12 reassurance shield is posted on the one mile overhead assembly for Exit 1B/Louisiana 3064/Essen Lane. This assembly is posted within 300 feet of the split from Interstate 10. Louisiana 3064 also intersects Interstate 10 at the next eastbound interchange (Exit 160). Photo taken by Eric Stuve (12/17/02).
Next Five Interstate Junctions for Interstate 10 east
Interstate 55 50 miles at LaPlace, LA
Interstate 310 61 miles at Kenner, LA
Interstate 610 71 miles at New Orleans, LA
Interstate 910/
Interstate 49
75 miles at downtown New Orleans, LA
Interstate 510 87 miles at east New Orleans, LA
Next Three Interstate Junctions for Interstate 12 east
Interstate 55 38 miles at Hammond, LA
Interstate 10 85 miles at Slidell, LA
-- --
Perspective from Interstate 10 west
Westbound Interstate 10 at Exit 160/Louisiana 3064/Essen Lane. This 1.86-mile state route connects Louisiana 73 and 427 and provides the first mainline interchange for Interstate 12 (Exit 1B) just to the north. Photo taken by Chris Patriarca (04/13/03).
Interstate 10 westbound maintains just two lanes as it continues toward downtown Baton Rouge at Exit 159/Interstate 12 east. Photo taken by Chris Patriarca (04/13/03).
Interstate 12 eastbound begins from Interstate 10 westbound. The area of southeast Baton Rouge is rather developed, so a return ramp to Interstate 12 eastbound is useful for local traffic interests. Photo taken by Chris Patriarca (04/13/03).
Next Three Interstate Junctions for Interstate 10 west
Interstate 110 4 miles at downtown Baton Rouge, LA
Interstate 49 56 miles at Lafayette, LA
Interstate 210 125 miles at Lake Charles, LA
Eastern Terminus - Interstate 10/Interstate 59 - Slidell, Louisiana
Perspective from Interstate 12 east
The first of in a series of Exits 85A/B/C guide signs on Interstate 12. This 1.25 mile signage is posted at the U.S. 11 underpass of Interstate 12 at the Exit 83 interchange for Slidell. Speed limits of Interstate 12 are posted at 70 MPH from Exit 10 eastward to the terminus. Photo taken by Eric Stuve (12/17/02).
Now within one mile of the eastern terminus of Interstate 12 and southern terminus of Interstate 59. All current Interstate 12 related signage was installed during the Spring 2000 replacement project. Photo taken by Eric Stuve (12/17/02).
The first off-ramp of the final interchange of Interstate 12 is for Interstate 10 westbound to the city of New Orleans. This guide sign is the first such panel for Exit 85A, as the ramp departs in 0.50 miles. The overpass in the background is that of Louisiana 1091. Louisiana 1090 and 1091 parallel the Interstate 10/59 north-south alignment through Slidell between U.S. 11 and 190. Photo taken by Eric Stuve (12/17/02).
Entering the Exit 85 interchange on Interstate 12 eastbound. Exit 1A departs for Interstate 10 west (south) back to Slidell and New Orleans. This north-south alignment of Interstate 10 was once touted as Interstate 59 in planning maps. Photo taken 10/04/01.
The preceding set of guide signs on Interstate 12 eastbound at Exit 1A/Interstate 10 west. Interstate 10 actually enters the expansive city limits of New Orleans in just 11 miles. The municipal boundary extends outward to the Orleans/Saint Tammany Parish Line over Lake Pontchartrain. Photo taken 11/06/99.
A third perspective of Exit 1A of Interstate 12 eastbound. Interstate 10 sees three Slidell area exits before crossing the seven mile Lake Pontchartrain Bridge. The final mainline exit of Interstate 12 meanwhile, serves the northbound beginning of Interstate 59/Exit 1B. Photo taken by Eric Stuve (12/17/02).
Interstate 59 northbound begins from Interstate 12 eastbound at the Exit 1B cloverleaf ramp. The Interstate also sees a Slidell area exit, three miles to the north. Interstate 59 otherwise travels 11.48 miles to the Mississippi State line near Nicholson before reaching Hattiesburg in 73 miles. Photo taken 10/04/01.
Interstate 12 draws to a close at the merge onto Interstate 10 eastbound. There are no more Louisiana interchanges in this direction, as Interstate 10 crosses the Pearl River Wildlife Management Area into the Magnolia State in seven miles. Photo taken 10/04/01.
Perspective from Interstate 10 west
Interstate 10 spans the West Pearl River on the two mile approach to the joint terminus of Interstates 12 and 59. Photo taken 04/20/12.
The one mile guide sign for Exits 267A/B resides just west of the Louisiana Welcome Center. The Slidell welcome center reopened on June 29, 2009 after two years of reconstruction. The new facility replaced the 1978-opened center at the same location at a cost of $12 million.2 Photo taken 04/20/12.
The left-hand lane of Interstate 10 opens to allow for two lanes to New Orleans and the westbound mainline. Traffic to the right defaults onto Interstate 12 westbound (Exit 267B) in one half mile. Exit 267A departs shortly after the split of Interstate 10 from 12 for Interstate 59 north. Photo taken 04/20/12.
Interstate 12 splits and begins from Interstate 10 west. Both highways serve the immediate Slidell area with interchanges. Otherwise Interstate 12 reaches Hammond in 45 miles while Interstate 10 enters the heart of New Orleans in 38 miles. Exit 267A, the northbound ramp for Interstate 59, departs in 0.25 miles. Photo taken 04/20/12.
More photos from this perspective, including 2000-based sign replacements, at the Interstate 10 West - Mississippi to New Orleans East highway guide.
Historical Perspective from Interstate 10 westbound
A resigning project of Exit 267 resulted in new guide signage for all perspectives during the Spring of 2000. The product of this project saw the replacement of the original sign bridges and faded reflective signage. This photograph shows the sign bridge at the Interstate 10/12 split.
The overheads preceding the Interstate 10 and 12 split were replaced again by 2012 with Clearview-font based signs. Photo taken by Adam Froehlig (03/99).
Next Three Interstate Junctions for Interstate 10 west
Interstate 510 21 miles at east New Orleans, LA
Interstate 610 29 miles at New Orleans, LA
Interstate 910/
Interstate 49
34 miles at downtown New Orleans, LA
Next Three Interstate Junctions for Interstate 12 west
Interstate 55 47 miles at Hammond, LA
Interstate 10 85 miles at Baton Rouge, LA
-- --
Perspective from Interstate 59 south
The first sign for Interstates 10 and 12 west (Exits 1A/B/C) posted along Interstate 59 south is this nondescript junction panel situated north of the Louisiana welcome center. Photo taken 04/20/12.
A sign bridge, gone as of April 2012, was the first to display control cities for Interstates 10 and 12 west for southbound travelers of I-59. Interstate 59 south defaults onto Interstate 10 west to New Orleans as ramps (Exit 1A) connect with Interstates 12 west and 10 (Exit 1B) east to Bay St. Louis, Mississippi. Photo taken 08/20/01.
Exit 1A to the westbound beginning of Interstate 12 departs Interstate 59 southbound as it enters a directional cloverleaf interchange with Interstate 10. Interstate 12 travels west from the outskirts of Slidell to Covington and Baton Rouge. Photo taken 04/20/12.
Historical Perspective from Interstate 59 southbound
A resigning project during Spring 2000 resulted in the removal of this overhead Exit 1B guide sign assembly. The replacement, attached to the Brown Switch Road overpass in the background, was already replaced by 2012. Photo taken 11/06/99.
More photos from this perspective, posted at Interstate 59 South - Louisiana highway guide.
Perspective from Interstate 10 east
Exit 267B facilitates traffic to the westbound beginning of Interstate 12.
Interstate 59 will not encounter another Interstate highway until it merges onto Interstate 20 in 160 miles near the city of Meridian, Mississippi. Photo taken 04/20/12.
Yellow and black Left Exit tabs were included in 2012 sign replacements for Interstates 12 west and 59 north. The first interchange of Interstate 12 west lies two miles away at U.S. 11 (Exit 83). I-59 also next meets U.S. 11, with the US highway joining the freeway northward to Picayune, Mississippi. Photo taken 04/20/12.
More photos from this perspective, including 2000-based sign installations, at the Interstate 10 East - New Orleans East to Mississippi highway guide.
Next Three Interstate Junctions for Interstate 10 east
Interstate 110 53 miles at D'Iberville, MS
Interstate 65 104 miles at Mobile, AL
Interstate 110 162 miles at Pensacola, FL
Next Three Interstate Junctions for Interstate 59 north
Interstate 20
overlap begin
159 miles at Meridian, MS
Interstate 359 253 miles at Tuscaloosa, AL
Interstate 459 288 miles at Bessemer, AL


  1. "Signs on I-12 remind people of Florida Parishes republic." Fox 8 Live WVUE-TV New Orleans, November 24, 2003.
  2. "Booklet for I-10 Dedication Ceremony." Baton Rouge Digital Archive, September 18, 1964.
  3. "I-10 welcome center reopens near Slidell." The Times-Picayune, June 29, 2009.

Page Updated July 7, 2015.

Updates | About | Privacy Policy | Contact | © 1997- AARoads

State Louisiana
Mileage 85.59
Cities Baton Rouge, Slidell
Junctions Interstate 10, Interstate 55, Interstate 10/Interstate 59
Source: December 31, 2014 Interstate Route Log and Finders List
Interstate 12 Annual Average Daily Traffic

Parish From Exit: To Exit: AADT Comp. Year
East Baton Rouge Exit 1A/ I-10 east Exit 1B/ Louisiana 1068 106,183 2002
East Baton Rouge Exit 1B/ Louisiana 1068 Exit 2/ U.S. 61 98,967 2002
East Baton Rouge Exit 2/ U.S. 61 Exit 4/ Sherwood Forest Blvd. 90,163 2002
East Baton Rouge Exit 4/ Sherwood Forest Blvd. Exit 6/ Millerville Road 97,250 2002
East Baton Rouge Exit 6/ Millerville Road Exit 7/ Louisiana 3245 92,526 2002
East Baton Rouge Exit 7/ Louisiana 3245 Exit 10/ Louisiana 3002 76,337 2002
Liv. Exit 10/ Louisiana 3002 Exit 15/ Louisiana 447 42,857 2002
Liv. Exit 15/ Louisiana 447 Exit 19/ Liv. 45 39,046 2002
Liv. Exit 19/ Liv. 45 Exit 22/ Louisiana 63 35,855 2002
Liv. Exit 22/ Louisiana 63 Exit 29/ Louisiana 441 30,496 2002
Liv. Exit 29/ Louisiana 441 Exit 32/ Louisiana 43 34,896 2002
Tang. Exit 32/ Louisiana 43 Exit 35/ Louisiana 1249 35,000 2001
Tang. Exit 35/ Louisiana 1249 Exit 38/ Interstate 55 45,852 2001
Tang. Exit 38/ Interstate 55 Exit 40/ U.S. 51 Business 45,277 2001
Tang. Exit 40/ U.S. 51 Business Exit 42/ Louisiana 3158 44,964 2001
Tang. Exit 42/ Louisiana 3158 Exit 47/ Louisiana 445 41,533 2001
Tang. Exit 47/ Louisiana 445 Exit 57/ Louisiana 1077 39,475 2001
St. Tammany Exit 57/ Louisiana 1077 Exit 59/ Louisiana 21 42,678 2000
St. Tammany Exit 59/ Louisiana 21 Exit 63/ U.S. 190 39,937 2000
St. Tammany Exit 63/ U.S. 190 Exit 65/ Louisiana 59 40,396 2000
St. Tammany Exit 65/ Louisiana 59 Exit 74/ Louisiana 434 35,823 2000
St. Tammany Exit 74/ Louisiana 434 Exit 80/ North Shore Blvd. 31,873 2000
St. Tammany Exit 80/ North Shore Blvd. Exit 83/ U.S. 11 53,066 2000
St. Tammany Exit 83/ U.S. 11 Exit 85/ I-10/59 38,395 2000
Source: Louisiana 2002 Traffic Volume Monitoring (LADOTD)

The 1963 Louisiana Official Highway Map shows the westernmost two miles of I-12 as complete. This was shown correctly as under construction on the Baton Rouge inset.
Work was also underway after 1963 on I-12 from LA 447 and the Ponchatoula Bypass, the first portion of I-55 opened to traffic in Louisiana.
Interstate 12 was open from Baton Rouge east to U.S. 51 Business at Hammond by 1972.
Construction along I-12 continued in 1972 on the easternmost segment from LA 434 to I-10 and 59.