Louisiana/Highway Classification

A guide to classifying roads in Louisiana.

Important Regional Centers

These are major cities located in or near Louisiana.

Inside Louisiana

• Alexandria Alexandria
• Baton Rouge
• Lafayette Lafayette
• Lake Charles, Louisiana
• Monroe Monroe
• New Orleans
• Shreveport Shreveport

Outside Louisiana

• Pine Bluff, AR
• Texarkana, AR
• Gulfport, MS
• Hattiesburg, MS
• Jackson, MS
• Beaumont, TX
• Houston, TX
• Longview, TX
• Lufkin, TX

Highway Classification

LADOTD provides an open data map on highway classification which acts as a guide for tagging highways on OpenStreetMaps. In order to provide a universal standard across OSM, OpenStreetMap definitions will differ from LADOTD classification. It is recommended to review the 2021 Highway Classification Guide in order to understand OSM's definitions.

Louisiana's Classification Guide require a highway to meet several conditions based on LADOT's Functional Class, traffic control such as speed limits and weight restrictions, and local knowledge. For example a road may qualify as a Primary if it is a Minor Arterial AND starts and terminate at a Trunk. Or if it is a Major Collector but links a Motorway to a regional or international airport AND starts and terminate at a trunk.

OSM	OSM Definition	Example
motorway	Highway with no at-grade intersections and controlled access. All interstates in Louisiana fit this category.	I-10 Raceland-M.C. Expressway
trunk	Highways that are the best route between important regional centers and don't meet the physical criteria for motorway. Add expressway=yes to indicate sections of highway with enhanced infrastructure not quite to motorway standards.	US 171 US 61 Lake Pontchartrain Causeway
primary	A highway that meets at least two of the following conditions: Highway is classified as a Minor Arterial or higher by LADOT A major route that links directly to a Trunk or Motorway. Links trunk or motorway to important infrastructure such as major hospitals. regional or international airports, universities, sea ports, etc. Best non-trunk route between large commercial areas, place=suburb, place=town, or place=city. Use expressway=yes on Primaries that meet the OSM Definition of an expressway.	Old Jefferson Hwy US 71
secondary	A highway that meets two of the following conditions: Classified by the LADOT as Minor Collector or higher. Links tertiary and minor roads to a Primary, Trunk, or Motorway. Route connecting medium size commercial areas, place=quarter, and place=village to a primary, Trunk, or Motorway. Highway with minor weight restrictions, lower speed limits, low clearance, and other restrictions compared to a nearby primary but would be under-classified as a tertiary. Use expressway=yes on Secondaries that meet the OSM Definition of an expressway.	Tiger Bend Road LA 967
tertiary	A highway that meets two of the following conditions: Starts at a highway=residential, highway=unclassified, or highway with a higher classification and end at a secondary or higher classification. Route connecting place=neighbourhood, place=hamlet, and minor commercial districts to a secondary or higher classified road. A highway with a dead end but has wider lanes, higher speed limits, given priority through intersections, and less restrictions than nearby minor roads. Tertiaries that start as a dead end or "stub" MUST end at a road with a higher classification. City street that link non-residential service roads to secondary or higher classification.	Constitution Ave Old US 51 LA 958
Minor	Highways in residential areas not intended for through traffic may be considered a highway=residential road. A road not intended for through traffic but does not serve a residential area, qualify as a tertiary or higher classification, nor fit the definition of a service or track road may be considered an highway=unclassified road.

List of Motorways

A complete list of motorways in Louisiana based on consensus by OSM community. The sections "To" and "From" is meant only to provide a general idea of the connections between important regional centers within and outside Louisiana. Although most are direct connections, some may require changing from one motorway to another such as a route from Baton Rouge to Jackson, MS in which motorists would use I-12 and then switch to I-55 to reach Jackson. If "Motorway Status Starts/Ends" is blank then the motorway begins and ends in another state and is considered a motorway when passing through Louisiana. It is up to the state's local mapping community on when a motorway begin or end. Please check this list before adding or removing motorways.

This table duplicates information which is also tracked in Interstate Highways Relations. Please make sure both match.

Name	From	To	Motorway Status Starts	Motorway Status Ends
I-10 west I-10 west I-10 east I-10 east	New Orleans	Gulfport, MS Houston, TX Baton Rouge Lafayette Lake Charles
I-12 west I-12 west I-12 east I-12 east	Baton Rouge	Jackson, MS Hattiesburg, MS Gulfport, MS	I-10 (Baton Rouge)	I-10 (Slidell)
I-20 west I-20 west I-20 east I-20 east	Monroe	Texarkana, AR Jackson, MS Longview, TX Shreveport
I-49 south I-49 south I-49 north I-49 north	Lafayette	Texarkana, AR Alexandria Shreveport	I-10 (Lafayette)
I-55 north I-55 north I-55 south I-55 south	New Orleans	Jackson, MS	I-10 (LaPlace)
I-59 north I-59 north I-59 south I-59 south	New Orleans	Hattiesburg, MS	I-10 (Slidell)
I-110	Baton Rouge	Baton Rouge	I-10 (Baton Rouge)	US 61
I-210	Lake Charles	Lake Charles	I-10 (Lake Charles)	I-10 (Lake Charles)
I-220	Shreveport	Shreveport	Inner Loop Expressway	I-20 (Bossier City)
I-310	New Orleans	New Orleans	I-10 (Kenner)	US 90
I-610	New Orleans	New Orleans	I-10 (New Orleans)	I-10 (New Orleans)
I-910 (unsigned)	Westwego	New Orleans	I-10 (New Orleans)	US 90
Earhart Expressway	Harahan	New Orleans	Hamilton Street	Dickory Avenue
Inner Loop Expressway	Shreveport	Shreveport	I-220	LA 523
Raceland-M.C. Express	New Orleans	Lafayette	LA 308	Berwick Road South
Pineville Expressway	Alexandria	Alexandria	I-49 (Alexandria)	Shreveport Highway
US 90	Lafeyette	New Orleans	Captain Cade Road	East Main Street

List of Trunk Roads

This is a list of highways confirmed to be a trunk road by the OSM community. If "Trunk Status Ends" is blank, then the trunk status would end in another state and it is up to that state's local mapping community to determine where the trunk ends. Multiple locations in Trunk Status Starts/Ends indicate that the road becomes a motorway at certain points. Please check this list before adding or removing a trunk road.

Name	From	To	Trunk Status Starts	Trunk Status Ends
LA 6	Alexandria	Lufkin, TX	I-49
US 61	New Orleans	Memphis, TN	I-10
US 90	New Orleans	Lafayette	Carmadelle Street	I-10 (Contains several sections of Motorway status prior to ending at I-10)
US 165	Alexandria	Monroe	Pineville Expressway	US 425
US 171	Shreveport	Lake Charles	I-10	Inner Loop Expressway
US 425	Baton Rouge	Pine Bluff, AR	US 61
Lake Pontchartrain Causeway	New Orleans	Covington	I-10	I-12

Interchanges and Highway Links

When tagging a road as a Motorway Link, Trunk Link, Primary Link, etc. the link's classification must match the highest classified road it connects to. If a link connects a Motorway and Trunk then the link should be a Motorway. Links that connect a Primary and Secondary road should be tagged as Primary. This applies to any links from separated turn lanes to interchanges with on/off ramps. Please see the wiki's Highway _link page for more details.

Useful Resources

LADOTD Functional System Map