Functional classification is a system by which roads are classified using a set of criteria selected by the Federal Highway Administration (FHWA). These criteria include not only the physical attributes of the road but also efficiency of travel, number of access points, speed limits, route spacing, actual usage, and continuity. This can lead to quite different classifications for roads that appear similar. For example, a six-lane divided road in an urbanized area may be a Collector (Primary Street); a two-lane road through the middle of a town may be a principal arterial (Major Highway).
In Waze, functional classification is used to determine road type in the United States.
Functional classification is a national standard, but functional classification maps are published by state departments of transportation. Links to functional classification maps for each state can be found in the table below.
Reason for changes
The Waze forum holds a lengthy discussion on why the Functional Classification changes are being made.
Functional classification maps by state
|State||Interactive map||Static maps||Notes|
|Arkansas||ArcGIS Viewer||AHTD FC Overlay for ArcGIS - To use the overlay, click on the "Modify Map" in the upper right corner of ArcGIS. On the left side an "Add+" tab will pop up. Click on it and select "Add Layer from Web" and paste in this URL: http://gis.arkansas.gov/arcgis/rest/services/FEATURESERVICES/Transportation/MapServer/8|
|California||California Road System (CRS) Maps||Caltrans||Caltrans Earth has been replaced by California Road System (CRS) Maps|
|District of Columbia||DDOT|
|Florida||FDOT's Downloadable GIS files||See Southeast Region Wiki||Please DO NOT use the FDOT Enterprise IMAP for doing Functional Classification Changes. It is out of date.|
|Georgia||Georgia DOT||Atlanta Metro||Note that these maps are years out of date. Confer with the Waze State Manager before making large changes.|
|Hawaii||Hawaii DOT||The updated HDOT GIS Website requires the Adobe SVG Viewer.|
|Illinois||Getting Around Illinois||Illinois DOT||If interactive and static map disagree, use the interactive map classification and please notify Illinois SM's of the road and map in error.|
|Indiana||INDOT FC Layer|
|Kentucky||KYTC Functional Class||Kentucky Transportation Cabinet|
|Louisiana||LaDOTD Interactive Online Map||LaDOTD|
|Maryland||MD SHA via nzahn1||MD SHA||Interactive Maps transformed from MD SHA data to Google Earth(.kml) by nzahn1|
|Massachusetts||Road Inventory Map||massDOT||Select Federal Functional Classification from pulldown list on Road Inventory Map.|
|Michigan||MDOT PR Finder||MDOT|
|Nebraska||Nebraska Department of Roads|
|New Hampshire||New Hampshire DOT|
|New York||NY State DOT FC Viewer|
|Pennsylvania||PennDOT||In the MPMSIQ map, use the operational > FC layer. <br\>Information in the older static maps is out of date.|
|Rhode Island||RI Division of Planning|
|South Carolina||SCDOT GIS/Mapping|
|Texas||TxDOT Statewide Planning Map|
|West Virginia||WV DOT|
|Wyoming||WYDOT||Appears on U.S. Forest Service - WYDOT Liaison Program|
Other urban FC maps appear on various WY city government pages