[Talk-us] US Trunk road tagging

[Paul Johnson]

On Wed, May 5, 2021 at 2:22 PM MoiraPrime <MoiraPrime at pm.me> wrote:
>
> I personally think we should do the following
>
> 1. Trunks should connect to other Trunks or a Motorway on both ends if possible. No Isolated islands.

I feel like this generally wouldn't reflect ground truth.

> 2. Motorways should be longer than 1 mile, be an incomplete under-construction interstate, or be connected to another motorway. Random short island sections of interstate existing solely because someone thinks an interchange meets motorway quality should not exist (which is a repeated topic in the OSM US Slack).

I'd say wholly grade separated, controlled access and dual carriageway
with no at-grade intersections including at the ends.  Downgrade to
link or some other classification at the last controlled interchange.

> 3. Trunks should be important roads that fill in gaps in the Interstate system between two large cities. This can be 4 lane US highways, but it can also be 2 lane US highways, 4 lane state highways, you get the idea. The main idea is that the road is filling an important gap in the interstate system.

That's what we have highway=primary for.