[Talk-ca] Tagging of roads in Vancouver

Adam Dunn dunnadam at gmail.com
Thu Oct 7 18:09:39 BST 2010


You've hit upon a problem in mapping. There are basically three ways to
assign classification to roads:
1. Official government department classification (is it federal or
provincial or municipal and is it a major numbered highway (Hwy 1, Hwy 405)
or a minor numbered highway (Hwy 4A))
2. Importance to the area's road network (for the most part, this would be
similar to 1 above, but not always)
3. Physical construction design (number of lanes, divided or not, stop
lights at intersections or freeway with interchanges...)

2 and 3 can be very different from each other. For example, here in
Chilliwack (a city of ~70,000 people), the main road on the south side of
the highway is Vedder Road. It is 2 lanes in each direction and gets a
significant amount of traffic on it, but it's the responsibility of the
municipal government, and if it were unavailable (say an earthquake destroys
it), people could just take Evans Road or Prest Road so it's not of critical
importance. On the other hand, Highway 1 through Yale and Spuzzum is only 1
lane in each direction with no divider, but it's obviously a major route
with both provincial and federal funding, and if it were missing, people
would have to travel for several extra hours.

So if we were to tag based on physical construction, Vedder Road would be
ranked higher than Hwy 1, but based on importance Hwy 1 gets the higher
ranking. That's why we tend to prefer importance over construction. Now how
do we determine local importance?

OpenStreetMap was started in the UK, and luckily for them they have a
systematic way of numbering their roads. A roads are trunk, B roads are
primary and secondary, C roads are tertiary, suburban roads are residential,
and rural roads are unclassified. Thus OSM tagging was designed to match
this very closely, and many of the definitions on the wiki were originally
geared toward this (the wiki has become more generalized since then). In
Canada we don't have such a convenient lettering/numbering system so it's
more difficult to agree on how to tag things.

According to the BC page on OSM's wiki [
http://wiki.openstreetmap.org/wiki/Canada:British_Columbia], the roads that
should be tagged trunk are {1, 2, 3, 5, 11, 8th Ave/15, 16, 17, 19, 97(A, B,
C), 99}, the ones to tag primary are "all other primary provincial
highways", and secondary would be "secondary highways"

So...
If you see something that doesn't make sense, then feel free to ask away
here on the mailing list, just like you did. I can see that trunk isn't
being used at all in Vancouver (Mapnik renders them green, but the only
green roads in the GVRD I see is Hwy 17 to Tsawwassen, but 15 and 99 should
also be trunk), so even the guidelines aren't being followed. I agree with
you that there needs to be some reclassification to make things consistent.
The 99A/1A should probably be upgraded to primary. Did you want to do that
(have you done editing before)? Do you think 10th Ave East should be
downgraded or left as secondary? If we were to upgrade Oak and Granville,
then should we also upgrade Cambie, Main, Knight, King Edward, Hastings and
Broadway, or would this be too much; do we want to reserve primary for
separated highways that didn't make it on the trunk list above?

I've said it before, but I think we will eventually have a "highway love"
week, where we spend a week discussing the classification of various
highways throughout Canada. This will probably come once roads for 95% of
the population has been imported (ie NRN/Canvec has been imported for xx3
and south, sorry territories).

Adam


On Thu, Oct 7, 2010 at 6:24 AM, Paul Norman <penorman at mac.com> wrote:

> The big issue I'm having around New Westminster is that everything is
> tagged
> residential, with the few streets that are tagged all being tagged as
> secondary I've tagged some of the major residential collectors.
> Some examples.
>
> 10th Ave (99A/1A) is tagged as secondary, the same as 10th Ave East, which
> isn't part of the 99A/1A, and has two lanes and is of a quite different
> character. These are both tagged the same as the Lougheed Highway in the
> Burnaby/Coquitlam region, which is a 4-6 divided highway.
>
> It seems like the only tanks in use are essentially secondary, motorway,
> and
> residential.
>
> To me it would make more sense if the major routes such as Lougheed,
> Kingsway, 99A/1A, Granville, Oak, etc were primary, with routes like the
> Lougheed where it is divided and the Mary Hill being tagged as Trunk or
> Motorway since they are divided highways with very few intersections.
>
> -----Original Message-----
> From: talk-ca-bounces at openstreetmap.org
> [mailto:talk-ca-bounces at openstreetmap.org] On Behalf Of Richard Weait
> Sent: Thursday, October 07, 2010 5:46 AM
> To: talk-ca at openstreetmap.org
> Subject: Re: [Talk-ca] Tagging of roads in Vancouver
>
> On Thu, Oct 7, 2010 at 8:24 AM, Paul Norman <penorman at mac.com> wrote:
> > I've been looking at the tagging practices in the lower mainland and
> > the documentation on the wiki. I'm having trouble finding a consistent
> > practice, particularly around residential collectors.
> >
> > Is there a consistent practice?
>
> Well there should be some consistency.  Can you link to areas that concern
> you?  Let's have a look.
>
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