[Accessibility] How to map parts of tactile paving and other feature?
anncopal at gmail.com
Mon Aug 2 10:02:25 BST 2010
>> I marked the nodes of crossings with traffic signals like this:
>> highway = traffic_signals
> Not correct, because highway=traffic_signals ist he node where the street is crossing the street.
> The pedestrian crossing is crossing=traffic_signals.
>> crossing = island (if there is an island in the middle of the road)
> Islands are best represented by splitting up the tracks of the road.
> Crossing=island does not help to prevent cars from trying to turn there,
> and the curbs can not take more attributes...
> So a pedestrian crossing with a traffic island is mapped as two pedestrian crossings...
> Closer to reality.
Clear to me and I will correct the streets in case of islands.
>> traffic_signals:sound = yes
>> tactile_paving = yes
> It is not clear, what is meant by adding tactile_paving to a single node in the middle of the crossing.
> There are many pedestrian crossings, that can be with or without tactile paving on one or none or both sides.
> Have a node for every single spot on the ground with or without tactile paving where the curb is.
> That is what is needed.
> Also tactile_paving can be on the pedestrian crossing itself, if there is a guiding line over the street (seldom!).
Oke. I already started marking the nodes on both sides of the
crossing, and will correct the crossing noded.
>> And other crossings, with only tactile paving, but no other markings
>> like this:
>> highway = crossing
>> crossing = unmarked
> What is this?
According to the Wiki this is how to mark crossings without any
markings (so no zebra or anything). I used them where the foot-way
crosses a side-way without any marks, but with tactile paving at both
sides of the crossing... Still here also the above applies, that the
node itselve is not where the tactile paving is, so I shall correct
that. Is it worth marking these crossings as "unmarked" or is there no
application for that information?
>> tactile_paving = yes
> On node? On way? See above.
>> I will start adding foot-ways right away... Grave (NL) is not such a
>> big town, and I know it well enough to do most of them from memory and
>> field-check the rest.
> Tactile paving needs very correct coordinates - There is no way to add it from your memory.
> The navigation software for the blind will even try to reach more GPS accuracy with DGPS sooner or later,
> So the accuracy is planned to come to what a blind person can detect with a white cane.
Most of the paving is right next to the streets, so doing is from
memory will gain the same accuracy as the already mapped streets (AND
source data). The only problem is that the OSM data are centerlines
and do not represent the actual width of the road on the map. So
putting cycle and foot-ways along streets means you still need to keep
some space between the centerline of the street and that of the
Here I have another question: I have a GPS receiver with a <3m
accuracy (tested and confirmed myself on holiday trips in Austria en
Google Maps). The tracks show an offset compaired to parts of the OSM
(AND data). What to do? This is the best accuracy I can get and it
means that tracks (multiple tracks of the same trace) apear to run
trough buildings... What is the expected accuracy for DGPS? And what
are your experiences with the accuracy of the imported AND data? This
is very important to decide what to trust: my GPS data or the current
> Any inaccurate mapping will confuse the blind people - a good FIXME="track for tactile_paving" is more welcome than a 9m offsite tactile_paving=yes...
> Best regards
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