Editing Interstate 12 (section)

{{Short description|Interstate Highway in Louisiana}}
{{Use mdy dates|date=March 2023}}
{{Use American English|date=March 2023}}
{{Infobox road
| state = LA
| type = I
| route = 12
| alternate_name = Republic of West Florida Parkway
| map = {{maplink-road|from=Interstate 12.map}}
| map_custom = yes
| map_notes = I-12 highlighted in red
| length_mi = 85.59
| length_ref = <ref name="FHWA">{{cite web |last=Starks |first=Edward |date=January 27, 2022 |title=Table 1: Main Routes of the Dwight D. Eisenhower National System of Interstate and Defense Highways |url=https://www.fhwa.dot.gov/planning/national_highway_system/interstate_highway_system/routefinder/table01.cfm |access-date=March 20, 2023 |work=FHWA Route Log and Finder List |publisher=[[Federal Highway Administration]]}}</ref>
| established = 1967
| direction_a = West
| terminus_a = {{jct|state=LA|I|10}} in [[Baton Rouge, Louisiana|Baton Rouge]]
| junction = *{{jct|state=LA|US|61}} in Baton Rouge
*{{jct|state=LA|I|55}} in [[Hammond, Louisiana|Hammond]]
*{{jct|state=LA|US|190}} between [[Covington, Louisiana|Covington]] and [[Mandeville, Louisiana|Mandeville]]
*{{jct|state=LA|US|11}} in [[Slidell, Louisiana|Slidell]]
| direction_b = East
| terminus_b = {{jct|state=LA|I|10|I|59}} in Slidell
| parishes = [[East Baton Rouge Parish, Louisiana|East Baton Rouge]], [[Livingston Parish, Louisiana|Livingston]], [[Tangipahoa Parish, Louisiana|Tangipahoa]], [[St. Tammany Parish, Louisiana|St. Tammany]]
| previous_type = US
| previous_route = 11
| next_type = LA
| next_route = 12
}}
'''Interstate&nbsp;12''' ('''I-12''') is an intrastate [[Interstate Highway]] located entirely within the [[US state]] of [[Louisiana]]. It spans a total of {{convert|85.59|mi|km}}<ref name="FHWA" /> in an east–west direction from [[Interstate 10 in Louisiana|I-10]] in [[Baton Rouge, Louisiana|Baton Rouge]] to an interchange with both I-10 and [[Interstate 59 in Louisiana|I-59]] in [[Slidell, Louisiana|Slidell]]. Along the way, it passes through the city of [[Hammond, Louisiana|Hammond]], where it intersects [[Interstate 55 in Louisiana|I-55]] and [[U.S. Route 51 in Louisiana|US Route&nbsp;51]] (US&nbsp;51). It also serves the cities of [[Ponchatoula, Louisiana|Ponchatoula]] and [[Denham Springs, Louisiana|Denham Springs]], as well as the [[St. Tammany Parish, Louisiana|St. Tammany Parish]] cities of [[Covington, Louisiana|Covington]] and [[Mandeville, Louisiana|Mandeville]].

I-12 parallels the older [[U.S. Route 190 in Louisiana|US&nbsp;190]] corridor and traverses the north shore of [[Lake Pontchartrain]] in the southeastern portion of the state. The Interstate's length is [[List of Interstate Highways|short for a mainline Interstate]] and is comparable with the country's longest [[auxiliary Interstate]]s. It is one of the shortest mainline Interstates to terminate at the same route (I-10) at either end. Apart from serving the various communities of the [[North Shore, Louisiana|North Shore]], I-12 acts as a long [[Bypass (road)|bypass]] of New Orleans and is heavily used as a shortcut for through traffic on I-10. While I-10 curves to the south to pass through the city limits, I-12 takes a more direct alignment, reducing the distance between Baton Rouge and Slidell by about {{convert|22|mi|km}}.

In 1993, the [[Louisiana State Legislature]] designated I-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]] (DOTD) in order to highlight the unique history of Louisiana's [[Florida Parishes]].

Louisiana is in the process of widening I-12 to three lanes in each direction in locations such as Covington and Mandeville where the Interstate is still two lanes in each direction.