[Talk-us] Bike route relation issues
steveaOSM at softworkers.com
Sun Jan 11 19:54:07 UTC 2015
Kerry Irons writes:
>By the logic that I-5 in Oregon is tagged as a bike route, then all
>roads in the US that don't prohibit bicycles should be tagged
>likewise. Obviously that "logic" is incorrect. There is no body,
>official or otherwise, that calls I-5 in Oregon a bike route.
Agreed: see below about the map referenced by Clifford Snow which
only notes that I-5 "is" an Interstate highway. No suitability or
legality for bicycles is expressed (though it may be implied) by
Oregon's DOT map.
The legend on Oregon's State Bicycle Map, shows Interstate Freeways
simply designated as such (and "diminished" by map color semiotics --
making them gray), no suitability or legality of Interstates for
bicycles is expressed, though it may be implied by being a "lesser
semiotic." (As in, "poor choice upon which to bicycle.") The map
legend also denotes "Highway Shoulder Width 4' or More" (prominent:
thick with red casing), "Highway Shoulder Width Less then 4'" (yellow
and thinner) and "Paved/Gravel Road Without Shoulder Data" (thinner,
less prominent lines yellow with gray casing or gray and very thin).
Importantly, no specific mention is made about the legality of
bicyclists on any particular road. So I come to a conclusion that
Oregon's DOT makes no assertion of bicycle legality on any road, AND
does not express any particular bicycle routes, at least with this
Let us recall that it is longstanding correct data entry in OSM to
enter physical infrastructure tags for bicycles (such as
"cycleway=lane") as well as logical infrastructure tags for bicycles
(route relation data such as network=rcn). Both might be determined
from either "on the ground" real world data such as paint on the
asphalt (physical) / a "Local Bike Route Number 44" sign (logical) OR
from published/printed (by a government official body) data such as a
map of a local or state bicycle route network. However, in the
latter case of describing logical infrastructure, actual signs make
route data unambiguous to put into OSM, whereas a published map
without signs is a bit more controversial. I argue that a government
body which says "a logical bike route exists on these segments of
physical infrastructure" (but without signs) means that OSM can
correctly contain a bicycle route relation reflecting this. This is
the "on the ground verifiability" issue regarding signed vs. unsigned
(logical) bicycle routes. We should not confuse this with using
proper tags (cycleway=lane...) to describe physical bicycle
infrastructure, or whether bicycling is legal on a particular segment
of physical infrastructure: these are different but related issues.
James Umbanhowar writes:
>The GDMBR issue seems to be a conflict between tagging for the
>renderer and tagging for the router...My opinion is that the road
>ways themselves should be tagged as unpaved (or tracks as many
Agreed, though this does not seem a conflict between tagging for the
renderer and tagging for the router: tags highway=track and
surface=gravel suffice to describe physical infrastructure, route=mtb
and ref=GDB suffice to describe logical infrastructure. These
accurately and sufficiently tag, and renderers get them right (well,
they do or should). Additional tags (width=...) might not render,
but if accurate, can be helpful.
>The I-5 thing seems strange. That is not a separate "bike route"
>but rather an interstate highway that allows bicycles. bicycle=yes
>on all the component ways should be sufficient.
I do not agree: again, I find no evidence (from the Oregon DOT map)
that bicycles are explicitly designated "legal" on I-5. It may be
the case that explicit statute specifies bicycles are allowed on I-5
in Oregon, but this map does not explicitly do so. Again, please
note that no specific "bike routes" are designated on that map,
either. It simply displays some highways as Interstates and some
highways as containing wide shoulders or narrow shoulders. While not
complaining about Oregon's DOT helping bicyclists better understand
where they might or might not ride a bicycle in that state, I
characterize these map data as "early" or "underdeveloped" w.r.t.
helpful "bicycle routing" by a DOT.
And Richard Fairhurst asks:
> > What does the community think?
There are many issues here. One (e.g. in Oregon re: I-5) is whether
"any" road which is legal for bicyclists should be 1) tagged with
"bicycle=yes" and 2) be part of a bicycle route relation. From our
United_States/Bicycle_Networks wiki, if a road or cycleway is tagged
with a (local) "Bike Route" sign, "without labeling or numbering of
routes, ways marked as bike routes should be tagged lcn=yes, either
directly or as members of a route relation." This makes sense, but
it is not 1) above, it is more like 2). If a government body has
posted Bike Route signs, it is clear we want lcn=yes. If a
government body has published a map explicitly denoting a bicycle
route (whether numbered, named or simply identified), I believe we
can reasonably enter that into OSM, even without signs. (I realize
this is controversial w.r.t. OSM's "on the ground verifiability"
maxim). But if a government body has simply made bicycling legal on
a particular CLASS of roadways, I don't believe we need explicitly
tag it that way, lest we clutter the map, as bicycling is
specifically allowed on many (perhaps even most) roads in the USA.
Exceptions reasonably arise, for example, on sections of freeway
(motorway) where bicycles ARE allowed, where it seems to make sense
to tag bicycle=yes as it may otherwise be reasonably implied that
freeway (motorway) is bicycle=no by default.
James Umbanhower's point about bicycle=yes on I-5 in Oregon (if
indeed they are actually allowed/legal) seems correct to me as well.
At least in the 50 states in the USA, it makes sense for OSM to start
with the assumptions that bicycles are legal on all roads and that
bicycles are not legal on freeways (motorways). We should then tag
exceptions where there are exceptions. If this is I-5 in Oregon,
then let us tag bicycle=yes on those segments. AND (also), if there
is an explicit (non-private/public) ROUTE, then put those segments
into a route relation. But I see no evidence to do this in the
instant case. (We can certainly be persuaded otherwise with
In short: bicycle tagging is reasonably separated into physical
tagging and logical tagging. The former denotes physical
infrastructure and/or (sometimes) whether bicycling is allowed/legal
on a particular physical facility. The latter denotes whether a
bicycle route logically exists on a set of physical facilities.
Sometimes signs exist to denote a logical route (in which case it is
unambiguously a bicycle route), sometimes no signs exist, but a
government body publishes a map or description of the route, in which
case it really does "exist" in real world, but may be difficult or
impossible to determine by "on the ground" verifiability. This
latter case still does stir controversy in OSM, but we do continue to
discuss this in ways which are productive and helpful for OSM's
longer term future.
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