[OSM-talk-ie] Traffic Islands, pedestrian areas and footways for routing purposes

Tue Dec 22 22:14:10 UTC 2015

I marked this along with other mails to reply to and somehow missed it so
apologies for the late reply

I took a quick look in taginfo [1] (we also have a version for Ireland
incase people didn't know [2]) and in the wiki and the most used option is
traffic_calming=island (14k)

There is also landuse=traffic_island (2k uses). While neither way is wrong
per se, the traffic_calming one fits within the traffic_calming schema so
is probably the better option

There's some sparse detail on the wiki about it here [3] and here [4]

In terms of access, if there is a barrier running down the middle, map the
barrier as such e.g. barrier=fence etc

With regards to routing, you can test that out on the OSM site. I used your
O Connell Street example [5].

Something such as the meridian in OC Street, I'm not sure that would be
considered a traffic island?

1 - http://taginfo.openstreetmap.org/
2 - http://taginfo.openstreetmap.ie/
3 - http://wiki.openstreetmap.org/wiki/Key:traffic_calming - Bottom of page
4 - http://wiki.openstreetmap.org/wiki/Tag:traffic_calming%3Disland
5 -
http://www.openstreetmap.org/directions?engine=mapzen_foot&route=53.3474%2C-6.2595%3B53.3524%2C-6.2613#map=16/53.3499/-6.2603

Hope this helps
Dave

On Tue, Dec 8, 2015 at 3:04 PM, Conor <movinghouse at gmail.com> wrote:

> Hi all,
>
> Colm and myself raised an issue relating to pedestrianised areas and
> footways a month ago and there was no response at the time. This
> issues are ongoing and I'm wondering if anyone has an opinion a month
> later? I'll include Colm's and my own original messages below. Thanks
>
> =========
>
> Hi,
> I'm wondering what the best way is to deal with traffic islands - the
> parts of roads that aren't roadway / carriageway and aren't lateral
> footways / footpaths. Sometimes they are unmapped, sometimes they are
> mapped as pedestrian areas and/or pedestrian ways .
> On the road, they generally come in one of three fashions:1. No
> pedestrian access / no meaningful pedestrian use, e.g. Dorset Street
> Lower in Dublin, where  there are trees every 10 meters that block the
> way. Not mapped, other than as two separate roadways. Should these be
> mapped at all?
>
> https://www.google.ie/maps/@53.3599777,-6.261141,3a,75y,44.35h,85.42t/data=!3m7!1e1!3m5!1s0YTaJATDMDakjhiLjRa__w!2e0!6s%2F%2Fgeo2.ggpht.com%2Fcbk%3Fpanoid%3D0YTaJATDMDakjhiLjRa__w%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D219.34166%26pitch%3D0!7i13312!8i6656
> 2. Those where pedestrian access is an important part of their use,
> e.g. at the central median on O'Connell Bridge in Dublin. Mapped as
> pedestrian area linked to pedestrian ways at the south end, but not
> the north end, effectively making it a cul de sac. I'm not sure how
> route planners treat areas.
>
> https://www.google.ie/maps/@53.3470972,-6.2591266,3a,75y,90t/data=!3m7!1e1!3m5!1s7ed2ZerYJnbZnrW-0cHENQ!2e0!6s%2F%2Fgeo2.ggpht.com%2Fcbk%3Fpanoid%3D7ed2ZerYJnbZnrW-0cHENQ%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D94.366425%26pitch%3D0!7i13312!8i6656
> 3. Traffic islands at signaled junctions generally, e.g. at the
> junction of O'Connell Bridge / D'Olier Street / Westmoreland Street.
> Mapped as pedestrian areas and pedestrian ways.
> Thank you
> Colm
>
> =========
>
> Hi Colm,
>
> Perhaps you're the same Colm that I was in touch with on a similar
> subject a few days ago? If so, we had discussed raising this on the
> mailing list so either way this would be as good a time to add some
> further thoughts to the subject if that's ok. Apologies for the long
> read...
>
> The aspects you drew attention here to are really interesting as they
> highlight how differently all contributors to OSM can see the value,
> use and appeal of the map. I myself am more biased towards visual
> reading of maps (yes, that old fashioned way) and sometimes see people
> question the value of mapping something where I see no question at
> all. All valid questions though, of course. In my attempts at
> recommending OSM to various friends and work colleagues for actual map
> usage most try and use it for visual reading of a map (they generally
> find it doesn't work as well as Google for directions), whereas any
> friends who would be more technically inclined often find the routing,
> tools and contributing more appealing.
>
> I've come across a potential clash of solutions for drawing and
> tagging for routing applications vs drawing and tagging for visual
> applications on OSM. As mentioned above, people contributing to the
> map can be attracted to it for varying reasons and I caught a pattern
> occuring in lots of areas I was contributing to. Seeing that all
> applications and uses should be catered for as best as possible,
> myself and VictorIE (the same Colm?) got talking about our difference
> of opinions on the matter.
>
> The issue I raised revolves around the use of short, sporadic footways
> that appear in locations where there isn't a designated footway. In
> terms of visual mapping I am not a fan. I've seen them appear as
> multiple desire lines across fields or as someone's preference for
> where they may cross a traffic island on a busy road where there is no
> markings or crossing in real life. In this instance, an almost
> infinite combination of footways could be drawn across the traffic
> islands/fields and, although there are certainly exceptions where the
> footway aids in suggesting where to walk, it seems to benefit routing
> applications to the detrement of visual applications.
>
> Footways drawn in urban areas can be potentially confusing at
> communicating visually. I've seen understandable additions where
> they've been added in locations where the footway area is wide to give
> some visual sense to the void of space on the map between roads (e.g.
> some may read a large void between roads as potentially containing
> buildings/fields). In my opinion, the presence of a short footway on
> the map can suggest that there's something preferential to it over all
> the adjoining ones I assume are there in real life, or that there's a
> lack of others. Where the footway is wide, the limitation of an OSM
> way being uniformly thin can be hard to decipher when trying to be
> confident you're in the right location from a visual map reading.
> Pedestrian way areas solve most of the visual problem but don't help
> routing where it's needed with most routing applications, so a
> combination can be useful.
>
> Conversely, I've seen urban projects on OSM where a large collection
> of footways have been added to aid pedestrians. The sheer abundance
> removed some of the doubt I just mentioned though this is a
> controversial approach in that it can look incredibly messy if care is
> not given to the amount of ways running parallel. It also a rather
> luxurious addition that can take low priority given that most urban
> highways are assumed to have some form of footway neighbouring them.
>
> VictorIE correctly pointed out that OSM is a connection of joined up
> roads. A dominant use of OSM is for driving and the streets are the
> primary feature (the clue's in the name). It's essential that this use
> is adhered to for applications that provide directions and similar
> services. His own reason for the sporadic footways I'd seen in areas I
> was working on were to ensure roads were joined correctly for these
> services. The technicalities of this are not my forté but I would have
> thought there were other means to link roads for routing purposes. I
> also assumed that a routing application would not realise that a
> highway joining another highway was traversable only because a footway
> linked the two. (Amendment: Although OSM is a connection of joined up
> roads, I'd like to question that principle as it grows. For example,
> in rural parts of the country ther are many former donkey tracks that
> are invaluable for hikers. Many of these have overgrown in parts to
> the point that they do not exist in any form in sections. The sections
> that do remain are increidbly useful on a map but would be misleading
> and potentially dangerous if they are connected on OSM.)
>
> I originally discussed the issue with VictorIE after a footway added
> to a traffic island struck me as a particularly dangerous spot to
> cross at. There were no markings or designated footway in real life so
> I removed it out of worry. After he reinstated it I got in touch to
> figure this where he explained his reasons relating to routing. There
> was also a suggestion that doing so helped unclutter diagnostic tools.
> Again, in my opinion, I would give preference to solving problems with
> day to day usage of the map rather than solving problems on diagnostic
> tools. The latter should (and mostly does) aid in solving the first
> but should not be the target themselves if not confident it aids all
> day to day usage.
>
> Examples:
> http://www.openstreetmap.org/?mlat=53.38877&mlon=-6.07409#map=19/53.38877/-6.07409
> There are now two footways extending northwards off the looping
> driveway in front of the train station, to connect it to the footway
> running parellel against the station entrance. For routing, I see few
> issues as there's no wall blocking where they're drawn. Visually, they
> suggest to me that there is a designated way to walk here where there
> isn't. The left-most one is typically blocked by cars as it's a
> parking space. The right-most one is a dangerous spot to cross as it's
> a busy, wide road. There's a designated crossing-space further west
> from it that wasn't marked on the map.
>
>
> http://www.openstreetmap.org/?mlat=53.37103&mlon=-6.20664#map=19/53.37103/-6.20664
> As mentioned earlier. There is no designated pedestrian area where the
> footway's drawn. The traffic island is occasionally used by
> pedestrians but the way drawn is (in my opinion, I live nearby) a
> lethal part to cross as cars swing around the blind corner quite fast
> sometimes. Most people cross further up Collins Avenue (where there's
> still no designated crossing) when they've experienced a few near
> misses and often avoid the traffic island.
>
> I cannot see the sense in OSM working in such a way that this solves a
> routing issue at the detriment of visually reading the map (in any
> renderer).
>
> By the way, the fact that these little footways keep popping up just
> after I add new roads clearly indicates I'm doing something that is
> annoying diagnostic tools. I get no validation errors and the nodes
> are joined correctly. What should I be doing in terms of routing
> validation to stop annoying those who take the time to check for these
> errors on diagnostic tools (amendment: or are this particular error
> redundant as it's encouraging visual mapping difficulties?)
>
>
> Thanks,
>
> Conor
>
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