Re: [Talk-us] I 85 Express Lane (Atlanta, Georgia)

[Tod Fitch]

> On Sep 24, 2017, at 5:22 PM, Minh Nguyen  wrote:
> 
> On 22/09/2017 09:46, Jack Burke wrote:
>> My questions are:
>> * Should this lane be drawn as a separate way?  Legally, you cannot enter or 
>> exit the lane except at the designated sections, so drawing it separately 
>> makes things simpler for routers.  If it's drawn separately, a pair of 
>> motorway_link roads would need to be added at several places (the 
>> dashed-stripe sections).  The Lanes wiki page[4] seems to say that it should 
>> be drawn separately:  "If one or more lanes of the road are restricted to 
>> high-occupancy vehicles (typically vehicles with 2+ occupants, although this 
>> varies by jurisdiction). Most useful if entrance/egress is permitted at any 
>> point along the route; if entering or exiting the HOV lane(s) is only 
>> permitted at certain locations, modeling the HOV lane(s) as separate ways is 
>> preferable."  (Even though that says HOV, the same reasoning appears 
>> relevant for toll.)  Does everyone concur with this construction?
> 
> I might be inclined to map the lane as a separate way, but only because I 
> don't know of any routers that currently recognize the change:lanes tag. [1] 
> Either way, it makes sense to treat HOV and toll lanes similarly.
> 
> [1] https://wiki.openstreetmap.org/wiki/Key:change
> 

I strongly recommend mapping them as one way with the hov:lanes=* and 
change:lanes=* showing the restrictions and where you can transition between 
the lanes. That is the best tagging I know of to accurately reflect the actual 
configuration.

The reason I feel strongly about it is that many miles of HOV lanes in my are 
were mapped as separate lanes (done before I moved to the area). And now 
CalTrans is repainting those to allow entry and exit at anyplace (change from a 
variety of old paint styles to broad dashed white striping). If the HOV lanes 
had been tagged as a single way with change:lanes showing the restrictions on 
moving to and from the non-HOV lanes it would have been trivial to change the 
mapping to conform to the current paint. Mapped as separate ways you have to go 
back and remove the separate ways then the paint changes which is a pain.

When there is a solid line (I’ve seen white, yellow and a variety of parallel 
white/yellow versions of the “don’t change lanes here striping), there are 
generally designated areas for transitioning between HOV and non-HOV lanes. If 
you map the HOV as a separate way then you need to add any number of virtual 
cross over ways. I wondered why OsmAnd and Maps.me were always telling me to do 
slight rights or slight lefts in those areas until I looked at the mapping and 
saw the separate HOV lanes with virtual link ways connecting it to the non-HOV 
lanes. In essence putting in separate HOV ways where they don’t actually exist 
doesn’t always help the router.

FWIW, the JOSM plug-in that deals with change:lanes shows things nicely. And I 
suspect that routers like OsmAnd will be supporting it soon (if not already) as 
they support turn:lanes pretty well.

Extending this somewhat: I’ve traditionally mapped on and off ramps with the 
link leaving/joining the main way where the painted line becomes solid. With 
the relatively recent addition of change:lanes=*, I am wondering if the ramps 
should join the freeway at the actual physical point and the short lengths of 
acceleration/deceleration lanes which are physically part of the main traveled 
way be shown as another lane with change:lanes tagging to indicate where you 
are not supposed to cross.
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Re: [Talk-us] I 85 Express Lane (Atlanta, Georgia)

[Minh Nguyen]

On 22/09/2017 09:46, Jack Burke wrote:

My questions are:

* Should this lane be drawn as a separate way?  Legally, you cannot 
enter or exit the lane except at the designated sections, so drawing it 
separately makes things simpler for routers.  If it's drawn separately, 
a pair of motorway_link roads would need to be added at several places 
(the dashed-stripe sections).  The Lanes wiki page[4] seems to say that 
it should be drawn separately:  "If one or more lanes of the road are 
restricted to high-occupancy vehicles (typically vehicles with 2+ 
occupants, although this varies by jurisdiction). Most useful if 
entrance/egress is permitted at any point along the route; if entering 
or exiting the HOV lane(s) is only permitted at certain locations, 
modeling the HOV lane(s) as separate ways is preferable."  (Even though 
that says HOV, the same reasoning appears relevant for toll.)  Does 
everyone concur with this construction?


I might be inclined to map the lane as a separate way, but only because 
I don't know of any routers that currently recognize the change:lanes 
tag. [1] Either way, it makes sense to treat HOV and toll lanes similarly.


[1] https://wiki.openstreetmap.org/wiki/Key:change

--
m...@nguyen.cincinnati.oh.us


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Re: [Talk-us] guidelines regarding roads access

[Greg Troxel]

Adam Franco  writes:

> One additional note is that at least in my area, the TIGER import
> incorrectly added access=private to many driveways and privately maintained
> residential roads. Upon surveying these I've found that they are signed
> "Private" or "PVT" on the street-name sign to indicate
> private-maintenance/ownership (don't complain to the town about a lack of
> snow-plowing/grading), but do not in reality have an access restriction.

For a "private way" (legal term in my state for what I think you refer
to as "privately maintained residential road"), I agree that there
shouldn't be access=private.

For a driveway to someone's house, access=private seems right, in that
it's generally at least impolite to use that road other than as
visitor/delivery/etc.

Are you saying that you think access=private on say a 100m driveway from
a real public road to a single house should have no access tag (or
access=yes)?  If so, I don't understand why.

[Veering off into an adjacent topic...]

But, that tends to lead to pink blobs in rendering, and I'm not sure
that's the right thing, as service roads having the status "you should
use these only when dealing with the adjacent entities" seems to be the
default/normal case.  We should adjust rendering, not access, to make
this pleasing.

So I have been putting access=private on driveways for residences and
businesses that don't welcome the public (industrial) as I edit, and not
putting that on servie/driveways for businesses that do welcome the
public (retail and some commercial, more or less).

Part of the issue here is that when thinking about routing, humans know
that osm-ways that are private can be used if they are associated with
your destination (and you have permission/invitation to the
destination).  So perhaps we need some sort of association between ways
and destinations, but that seems like a lot of work, and a lot of bits
in the database, without a clear rationale to a win for routers.


I notice that OSMand has been asking (roughly) "destination is in/near
access=private; ok to use those"?  I'm not sure what I think of this; it
seems that it's normal to use access=private to get someplace if that's
what it takes, since the default assumption of "route me to X" is "it's
ok for me to go to X".  The hard part is if where you want to go isn't
on the same lot, and that private way just happens to be the closest.
This is usually because of a missing driveway for where you are going,
though, so it's reasonable to take the viewpoint that there's a map
error/omission and that the router behavior will be right once that's
fixed.


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