Mississippi/Mississippi Highways

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This page describes Mississippi-specific determinations for implementing US Highway Classification values.


Motorways are generally Interstate Highways, and highways built to Interstate Highway standards. Interstate highway standards include the following:

  • No at-grade intersections
  • controlled access
  • At least 2 lanes in each direction with emergency shoulders along most of the route.
  • All bridges must be fixed (no drawbridges)
  • Maximum speed limit of 70 mph on most of the route, with a signed minimum speed of 40 mph.

Additionally, roads classified as motorway must be motorway grade for at least 2 miles.The motorway grade ends at the first at-grade intersection, or the end of the route, whichever comes first.

Presently all non-auxiliary Interstate Highways in the state of Mississippi meet this criteria.


Interstate 110 in Biloxi features a drawbridge over the Biloxi Back Bay. While this does violate the fixed bridges rule, the bridge is rarely opened, and when it is opened, a 6 hour notice in advance of the opening is required except during hurricane evacuations, in which the bridge is then opened once every 30 minutes to allow boats to reach safe harbor.


Trunks are the most important non-motorway highways in an area. In Mississippi, we use the importance of the route in connecting two major regional centers together to classify Trunks.

Important Regional Centers

The following cities in and around Mississippi are considered important regional centers:

Inside Mississippi
  • Jackson, MS
  • Meridian, MS
  • Gulfport, MS
  • Hattiesburg, MS
  • Pascagoula, MS
  • McComb, MS
  • Biloxi, MS
  • Laurel, MS
  • Natchez, MS
  • Starkville, MS
  • Columbus, MS
  • Oxford, MS
  • Tupelo, MS
  • Greenville, MS
  • Vicksburg, MS
Outside Mississippi
  • Memphis, TN
  • Mobile, AL
  • New Orleans, LA
  • Alexandria, LA
  • Tuscaloosa, AL
  • Birmingham, AL
  • Monroe, LA
  • Little Rock, AR
  • Montgomery, AL
  • Baton Rouge, LA

Trunk Roads

The following routings are principal roads between pairs of important population centers not serviced by interstates.

From To Trunk Routing
Jackson, MS Starkville, MS MS 25
Jackson, MS Tupelo, MS MS 25, US 82, US 45 ALT/US 45
Jackson, MS Hattiesburg, MS US 49
Jackson, MS Mobile, AL US 49, I-59 (briefly), US 98
Jackson, MS MS Gulf Coast (Gulfport/Biloxi) US 49, I-59 (briefly), US 49, MS 67*, MS 605*
Meridian, MS Tupelo, MS US 45, US 45 ALT
Meridian, MS Columbus, MS US 45
Huntsville, AL Memphis, TN I-565, US 72, US 72 ALT*
McComb, MS Hattiesburg, MS US 98
Natchez, MS McComb, MS US 98
Hattiesburg, MS Natchez, MS US 98
Pascagoula, MS Meridian, MS MS 63, MS 57, US 45
Natchez, MS Baton Rouge, LA US 61
Laurel, MS Alexandria, LA US 84, LA 28
Natchez, MS Vicksburg, MS US 61
Oxford, MS Tupelo, MS US 278

*Additional Routing


Primary routes are non-motorway non-trunk routes for medium distance travel. They generally link medium-sized towns together with the trunk network.

In Mississippi, most 1 and 2 digit state highways qualify as primary. Most US Highways that do not meet the importance of trunk routes are considered primary as well.


Secondary routes are mid-importance roads that link smaller towns and communities together in rural areas. In cities they can link neighborhoods together.

In Mississippi 3 digit state highways are usually considered secondary routes.


Tertiary routes can be considered any route lesser in importance that is often used as a through route. In rural areas, this can usually be emphasized by the road being wide enough for two way traffic. Tertiary routes in rural areas may also be striped, although this is not a requirement for a Tertiary route.

Residential and Unclassified

highway=residential and highway=unclassified roads are the lowest on the tier list besides track.


Unclassified roads are roads that are slightly more important than residential roads, but not important enough to be Tertiary. This could be because they are a commonly used "shortcut", or because they're frontage/service roads along a main highway. They could even be roads that go through a business park.


Residential roads are roads that are mainly used for access to people's houses. Much like unclassified, they are roads not important enough for a tertiary+ classification. Due to the nature of the TIGER import, most routes in the US are tagged as Tag:highway=residential even if this is not their proper classification.

For rural roads that are too narrow for two oncoming cars to pass comfortably, and lack lane markings, consider adding a lane_markings=no tag.


highway=track roads are roads that are mainly used for forestry and agriculture.

Roads should not be labeled as track if they are named county roads that are unpaved. To reiterate, track is to only be used for roads that exist for forestry and agriculture. To demonstrate an unpaved county road properly, use residential or unclassified with a surface tag.