User:Compdude/Draft:Washington highways

This is a draft of content to use on the Washington page as replacement for the minimal road tagging guidance. It is based on discussions on Talk-us: US Trunk road tagging and the OSMUS Slack. Feel free to discuss or help edit this content prior to any inclusion on Washington.

This page describes Washington-specific determinations for implementing US highway classification values.

Important regional centers

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

• Seattle, WA
• Tacoma, WA
• Everett, WA
• Spokane, WA
• Olympia, WA
• Tri-Cities, WA (Pasco, Kennewick, and Richland)
• Yakima, WA
• Moses Lake, WA
• Aberdeen, WA
• Longview, WA
• Bremerton, WA
• Walla Walla, WA
• Lewiston, ID/Clarkston, WA
• Centralia/Chehalis, WA
• Coeur d'Alene, ID
• Vancouver, BC
• Kelowna, BC
• Portland, OR
• Astoria, OR
• The Dalles, OR
• Sandpoint, ID

Trunk roads

The following routings are the principal routes between pairs of important population centers, and not serviced by highway=motorway, and thus should be tagged highway=trunk.

From	To	Trunk routing
Everett, WA	Spokane, WA	US 2
Aberdeen, WA	Olympia, WA	US 12/ SR 8/ US 101
Aberdeen, WA	Centralia/Chehalis, WA	US 12
Centralia/Chehalis, WA	Yakima, WA	US 12
Tri-Cities, WA	Walla Walla, WA	US 12
Walla Walla, WA	Clarkston, WA/Lewiston, ID	US 12
Tri-Cities, WA	Spokane, WA	US 395
Clarkston, WA/Lewiston, ID	Spokane, WA	US 95/ US 195
Astoria, OR	Aberdeen, WA	US 101/ SR 401/ SR 4/ US 101
Aberdeen, WA	Port Angeles, WA	US 101
Seattle, WA	Port Angeles, WA	I-5/ SR 104/ US 101
Port Angeles, WA	Olympia, WA	US 101
Tacoma, WA	Bremerton, WA	SR 16/ SR 3
Bremerton, WA	Port Angeles, WA	SR 3/ SR 104/ US 101
Seattle, WA	Wenatchee, WA	I-90/ SR 970/ US 97/ US 2
Tacoma, WA	Yakima, WA	I-5/ SR 18/ I-90/ I-82
The Dalles, OR	Yakima, WA	I-84/ US 97
Yakima, WA	Wenatchee, WA	I-82/ I-90/ US 97/ US 2
Wenatchee, WA	Kelowna, BC	US 2/ US 97/ BC 97
Astoria, OR	Longview, WA	US 30/ SR 433/ SR 432
Wenatchee, WA	Moses Lake, WA	SR 28/ SR 281
Spokane, WA	Sandpoint, ID	US 2

Lower road classifications

Care should be taken to avoid over-classification - classifications should be broadly consistent across different regions, without areas of overall higher classifications than nearby places or similar areas. Spurs and dead-ends in classifications should generally be avoided, except when geography may demand it (e.g. roadways running up towards mountains).

Classification	Rural Areas	Urban Areas	Other notes
highway=primary	Major roads between cities. Note that the "main street" of a small rural town may not necessarily be primary; its importance to the road network overall is more important to classification than local importance.	Major arterials. Typically has some or all of these characteristics: Higher speed limits than other nearby roads Direct connections to freeways Spaced reasonably far from other primary roads Two or more lanes in each direction No stop signs	Most State Routes (which aren't already trunk or motorway) would be a good fit
highway=secondary	Minor roads between cities; less direct routes; important roads within small towns	Minor arterials. Typically includes some or all of: High speed limits (e.g. 30-35 mph) 1-2 lanes in each direction Fills in gaps in the road network between primary roads
highway=tertiary	Other minor roads. Paved and with lane markings/a center line.	Major collectors. Typically includes some or all of: Lane markings Typically has priority at intersections with non-all-way stops with lower-class roads Lower speed limits (20-25 mph, sometimes 30 depending on area) One lane in each direction
highway=residential highway=unclassified	Unpaved or otherwise poor-quality roads. In rural areas should be tagged as highway=unclassified; in towns and other residential areas, should be tagged as highway=residential.	Should almost always be highway=residential. Low speed limits Typically no lane markings Typically has to stop at intersections with other roads (unless uncontrolled)	Use highway=service where appropriate

In general, defer to local knowledge, especially in cases of potential ambiguity.