[Talk-us] Improving the classification of roads in SF

[Martijn van Exel]

Arun, 

Road classification has been discussed at length on this list, most recently I think in a lengthy thread started last September by Toby. 

There is no guideline for the United States that would unambiguously map every road to a class in OSM. Several pages on the wiki take a stab at this, most have not been maintained and partially contradict each other:
* https://wiki.openstreetmap.org/wiki/United_States_Road_Classification <https://wiki.openstreetmap.org/wiki/United_States_Road_Classification>
* https://wiki.openstreetmap.org/wiki/United_States_Roadway_Classification_Guidelines <https://wiki.openstreetmap.org/wiki/United_States_Roadway_Classification_Guidelines>
* https://wiki.openstreetmap.org/wiki/United_States_roads_tagging <https://wiki.openstreetmap.org/wiki/United_States_roads_tagging>
* Tangentially: https://wiki.openstreetmap.org/wiki/Highway_Functional_Classification_System <https://wiki.openstreetmap.org/wiki/Highway_Functional_Classification_System>
* Not US specific: https://wiki.openstreetmap.org/wiki/Talk:Highway_tag_usage <https://wiki.openstreetmap.org/wiki/Talk:Highway_tag_usage>

The core of the problem seems to be that there is no full mapping between the functional classification standards from the FHWA and the road network hierarchy.

We could learn from Waze, which has an excellent breakdown of highway types on their wiki: https://wiki.waze.com/wiki/Road_types/USA#A_hybrid_system <https://wiki.waze.com/wiki/Road_types/USA#A_hybrid_system> and https://wiki.waze.com/wiki/Road_types/USA#Highways <https://wiki.waze.com/wiki/Road_types/USA#Highways> further down on that page.

Perhaps an interesting BoF topic for SOTM US?

Martijn

> On May 11, 2016, at 9:07 AM, Arun Ganesh <arun.planemad at gmail.com> wrote:
> 
> While adding missing turn restrictions in SF using Mapillary around Market Street, i noticed that the classification of many of the roads seem inconsistent, especially since someone had retagged Market as tertiary (from primary?) after traffic restrictions that came into effect last year.
> 
> I did some quick retagging where it looked like new mappers had elevated the class of some roads and there were patches of secondary or tertiary roads among lower class roads, but the area could definitely use more eyes from locals to get it up to shape.
> 
> Is there any official classification that can be used as reference to make improvements?
> 
> -- 
> Arun Ganesh
> @planemad
>  <http://j.mp/ArunGanesh>_______________________________________________
> Talk-us mailing list
> Talk-us at openstreetmap.org
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