Missouri/Major roads/Main Discussion View history

Revision as of 22:18, 17 July 2019 by Herrchin (talk | contribs) (→‎Major_roads/Main: turning circle update)


Missouri Highway Types

Missouri has two types of state highways: primary (numbered) and supplementary (lettered). The table below shows the minimum classification for state highways. These are only minimums and may need to be upgraded based on the Functional Classification or the qualities defined on the road types Wiki page.

MO Hwy Type Waze Road Type
 Minor Highway 
 Primary Street 


State Highway Naming

Missouri primary numbered highways are named as MO-### (e.g. MO-13, MO-7 N). This includes their related business, loops, and spurs. (e.g. MO-13 BUS)

Missouri supplementary lettered highways are named as SH-xx. (e.g. SH-AA) This will pronounce via TTS as "State Highway A A". Lettered highways classified as 'Major Collector' according to MoDOT are designated as a Primary Street within Waze. This is because Major Collector in rural areas are not arterials that carry traffic over long distances. Additionally, these roads often lack shoulders and white fog lines. In other areas where MoDOT has classified a lettered highway as 'Minor Arterial' or higher, these would be designated as appropriate within Waze.

County Road Naming

County roads with the name designation of "County Road ###" are named as CR-### (e.g. CR-110). This shortened version takes up less space on the map screen and is announced correctly as "County Road ###" while navigating with the Waze app.

Farm Road Naming

Farm roads with the name designation of "Farm Road ###" are named as FR-### (e.g. FR-110). This shortened version takes up less space on the map screen and is announced correctly as "Farm Road ###" while navigating with the Waze app.

Functional Classifications

Missouri follows the Functional Classification (FC) system for the USA. Base minimum road types in the Waze editor according to the MoDOT Highway Functional Classification Maps along with guidance from the road type guidelines.

The table below shows a cross reference for the minimum road types in Missouri. Keep in mind that these are only minimums, and may need to be upgraded based on the qualities defined on the road type guidelines.


MODOT Classification Waze Road Type
  Interstate    Freeway 
  Expressway    Major Highway 
  Principal Arterial    Major Highway 
  Minor Arterial    Minor Highway 
  Urban Collector    Primary Street 
  Major Collector    Primary Street 
  Minor Collector    Primary Street 
  Local Road    Street 


Lock Levels

In Missouri we have a set minimum standard for locking roads based on segment type. Any road of a certain segment type must be locked at least to the rank (level) in the chart below. Roads may be locked higher for protection and special situations (areas with construction, tricky design, frequent mistakes, imaging inaccuracies, and the like), but should not be locked lower.

A great time to implement these locks is while bringing the road types of an area into compliance with the current US road type standards (FC and highway systems). Lock the roads based on type after they've been set to current US road type standards.

Missouri Minimum Locking Rank Standard
Segment Type Statewide
 Freeway  4
 Ramp  Highest rank of connected segments
 Major Highway  3
 Minor Highway  3
 Primary Street  2
 Street  1
 • • • • Ferry • • • •   5
 |-|-|-|-|-|-|-|-|-| Railroad |-|-|-|-|-|-|-|-|-|  2

U-Turns

U-turns are generally permitted in Missouri except where prohibited by state, local municipal law, or posted signage. U-turns are specifically prohibited at intersections controlled by a traffic signal. See MO Statute 304.341(2) for complete legal restrictions.

For Waze routing, u-turns should ONLY be enabled where they provide the potential for improved routing, which includes recovering from missed turns. A common example is a median-divided primary street that has homes/businesses with their driveways/entrances directly on it, where reaching them would otherwise require lengthy, multi-turn deviations through side roads in order to end up on the correct side of the median.

The u-turn must also meet the following criteria:

  1. The u-turn is explicitly allowed by signage or is otherwise legal and safe according to MO Statute 304.341(2).
  2. The turn can be completed in one continuous movement. This is not a specific legal requirement in Missouri, however would be good practice for safer navigation.
  3. There is at least 15 meters (49 feet) from the right edge of the legal departure lane to the right edge of the "destination" curb (49 foot turning circle).
  4. There is no sign prohibiting a u-turn.

Note that when editing, a functional u-turn can arise from more than just the u-turn flag on a road segment, such as with these common scenarios:

  1. Divided roads with box and partial-box intersections where the median segment is 15 m (49 feet) or longer.
  2. Divided roads with explicitly-mapped inside turn lanes unless the turn arrow in the u-turn direction is disabled.