[OSM-talk] Cycle lanes

[D Tucny]

On 25/03/2008, Sven Grüner <sven at schunterscouts.de> wrote:
>
> Bjørn Bürger schrieb:
>
> > Yes, but this is also the reality for cyclists. Everything involving
> > cycleways is actually a mess, unfortunately. That is, because a
> > bicycle is (mostly) not seen as an equal means of transportation.
>
>
> Being considered a fanatical biker by my friends as well I share that
> believe.
>
>
> > But on the map, each distinct lane/track of a cycleway should
> > be handled like e.g. the single lanes of a motorway/highway: Even the
> > tiniest cycle-lane beneath a street has a different usage profile,
> > different size and surface, different access rules, different right
> > of way, etc. than the street. So IMO it clearly needs it's own way.
>
>
> I can follow that argumentation based on the fact that dual carriageways
> get separate ways. But in my opinion those are just as unfortunate.
> Every traffic infrastructure (ie. road) consists of certain features
> which IMHO should be represented by one single object in our DB holding
> information about the features it's made from. I consider it really
> strange that we currently map two roads instead of one only because the
> real road has the feature "hard shoulder in the middle".


It would make sense to only need to tag a road once, no matter how many
parts it's made of, hopefully one day relationships will be handled well
enough by editors and renderers that that is what happens... If a road has
multiple parts to it, i.e. pavement, cycleways, multiple lanes in different
directions for different uses etc, you want to keep them all linked
together, tagged once, but, having separate sub-objects describing those
features has a use... You will probably need multiple relations though and
doing this is going to make the editors and renders more complex for sure,
even if it's just the code that gets more complex to try and keep the
interface simple...


Renderers can of course be trimmed to compensate all the disadvantages
> that come with this strategy or mappers can be encouraged to use
> relations to glue these together again but that's not really solving the
> problem, but creating workarounds for every purpose it encounters.


You could split the data into two or more datasets, with one, where
everything is recorded in as much details as possible as accurately as
possible, maybe even splitting every single lane including turning lanes,
and a second, where everything is recorded as single ways with each of those
ways containing lots of tags to try and describe things but loosing lots of
accuracy in the process...

Advantages and disadvantages to both... The hurdles to overcome when it
comes to rendering are probably pretty equal though... And think how much
effort would be involved in making two openstreetmaps... To me, getting all
the information possible recorded as accurately as possible would have to be
the goal, then no matter what you want to use it for, the data is there,
yep, it might be more difficult to work with than a simple dataset if you
only have a simple use, but, if you want to do something more complex then
not having the data makes it not possible...

I believe in relationships as being the key to pulling complex data together
and I believe in aiming for more detail than we can even have right now with
current tagging...

This worked fine when focussing on car-traffic but when we really want
> to provide high-quility (usable for routing/navigation) data of footways
> and cycleways I'm afraid we need a different approach.
>
> I'm not saying it's impossible by the way we do it now but I envision
> there must be a better way...
>
>
> > It will get easier, if support for that stuff is added to the editors.
>
>
> There are people who already believe our editors are too complex (not me).


I think there's definite room for relations being more polished/integrated
into the editors... Right now, the core functionality is there, but it's not
very usable for everyday mapping and tagging... I'm sure that's going to
improve over time though...

By the way, to follow the links to cycleways theme of the thread...
http://www.informationfreeway.org/?lat=30.276479076977562&lon=120.16459191145113&zoom=17&layers=B000F000F

This shows a junction of a dual carriageway with an elevated trunk dual
carriageway... Sandwiched between them is a cycle flyover...
This is one road that could benefit from more detail... to the west, the
road is actually wider with a wide pavement, curb down to cycleway,
barrier/garden, two lanes of traffic in one way, barrier/garden, bus lane
with curbing on the side it meets the next lanes, two more lanes of traffic
in one way, widening to 3 at points and all merging into 5-7 lanes at
junctions with solid lines in the middle and the same layout repeated on the
other side...
From a navigation point of view, this is a nightmare, you can only turn from
certain parts of the road, the barriers/gardens only have a few openings...

d
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