[Talk-us] Road classification

[mapboy at att.net]

Hi,

I hate to reopen an old subject but I'm not in agreement with the US classification system that exists.
>From reading past archive, it looks like this has been a contentious subject in the past.
I propose the following. I have already added it to some web pages as in my experience it's the best/most logical heirarchy that works. I apologize in advance if I'm stepping on any toes.

In OSM language the Highway feature is used to designate what we call roads. 

A motorway is a four+ lane, limited access, grade separated freeway. These can include Interstates, US Highways, State Highways, County Highways or even Farm to Market Roads if they meet certain criteria. These criteria are limited access,the use entrance/exit ramps to access the freeway. Intersections with other roads are at grade seperated crossings or ramps. A grade separated crossing means one road goes over or under the other. (ie. over/underpass) When Motorways meet other motorways they generally use ramps that are classified as Motorway Link. These motorways usually connect to other cities or move the traffic around and through a city. Limited access ring roads usually fall in this feature class also. 

A trunk is what a motorway becomes when it loses one of it's criteria. This usually occurs to US, State, County highways as they move outside the urban areas. Intersections with other roads can occur at grade and/or when ramps are no longer needed to access the road. Usually they remain 4+ lanes and may or may not be divided by a physical median. 

A primary road can be a US, State, County Highway or other road that connects two cities or moves traffic from one part of the city to the other. These are the highways that become Main St when they go through a small rural town. They will have traffic signals when they reach more densely populated areas. These are the roads you jump on when the freeway has an accident and you don't want to sit and wait it out. 

A secondary road moves traffic within a city. It would service only a certain area within a city. 

A tertiary road connects the residential roads to the higher classes: motorway, trunk, primary or secondary. 

I hope this clarifys things for some users. I know it's not going to please those who have already used other classification schemes.

thanks,
pete
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