Here's an example, where I used to live a short distance south of Alviso: http://www.openstreetmap.com/?lat=37.3851&lon=-121.9258&zoom=14&layers=B000FTF
See the light yellow roads that connect to other roads such as Montague Expressway and 1st St? Roads such as Lick Mill Blvd, Orchard Parkway, Plumeria? They're actually fair wide roads, and can have ~40 mph speed limits. The thing is, they're used only by people getting to local homes or businesses - they're not the main through routes. For San Jose, I've mentally come up with a system that's goes like this: Motorways are any and all limited access freeways - Highway 87, US 101, I-280 Primary highways are "Expressways" - or the few other roads that are similarly important. Montague Expressway, Lawrence Expressway, San Tomas Expressway, El Camino Real, Stevens Creek Boulevard: the heavy duty arterials. Secondary Highways are those roads you may take for a few miles, but are a little less important - such as Lafayette Street (which turns into Gold Street in Alviso - I wonder if I should have demoted it to a tertiary highway after it crossed under 237.) And then you have your tertiary roads. I've been subjective enough about this that I don't mind if some of these roads get reassigned, particularly in some neighborhoods I'm less familiar with. The San Jose map was in desperate need of having some sort of hierarchy of importance, so some areas I was less familiar with - such as East San Jose - I've tried to pick out the primary and secondary roads, without assigning tertiary roads. But hopefully, when you look at the map, you can quickly decide: what are the main roads I'd used to get to a neighborhood? What are the main roads within a neighborhood? That's another way to think of secondary and tertiary roads. -Alan ----- Original Message ---- From: David Carmean <[EMAIL PROTECTED]> To: Alan Brown <[EMAIL PROTECTED]> Cc: talk-us@openstreetmap.org Sent: Sunday, September 14, 2008 12:11:42 AM Subject: Re: [Talk-us] highway: tertiary? Alan, I live in the Bay Area and in fact will probably be augmenting some of your work down around Alviso and Sunnyvale; do you have any examples where you've actually chosen to use highway=tertiary? On Sat, Sep 13, 2008 at 09:57:52AM -0700, Alan Brown wrote: > I noticed the following suggested definitions for California for different > road classes: > > http://wiki.openstreetmap.org/index.php/California > > > For tertiary, they suggested > > > highway=tertiary > Lower traffic volumes on wide streets, or higher on narrow ones. > > > Kinda' vague .... and I'm not sure I'm in agreement with these definitions, > personally. I'd be even more vague :) . Here's what I think as someone who > worked in a map data company for a decade: > > _______________________________________________ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
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