[Tagging] Feature Proposal - TMC - New tagging scheme for TMC

fly lowflight66 at googlemail.com
Fri Apr 20 14:59:51 BST 2012

On 20/04/12 14:32, Heinrich Knauf wrote:
> Am 05.04.2012 04:27, schrieb Eckhart Wörner:

Thanks for you effort.

>> 4) Exits and entries
>> TMC specifies messages that apply to entries or exits, which I feel are not 
>> adequately represented in the proposal, even though the proposal mentions 
>> them. For example, assume that the 2nd exit slip road going west at Köln-Süd 
>> (where I already discovered the new tagging) is closed (and I believe there is 
>> a TMC message for that). How do I find this 2nd slip road? (Yes, I picked a 
>> really hard one.)
> Isn't that just a matter of the granularity of TMC location coding versus OSM
> mapping? If so, then there's nothing to help about that with any TMC tagging
> scheme whatsoever.

I am not that into TMC but I thought there is a difference between a TMC Point
and TMC Roads/Segments and that either a TMC Point might be blocked or some part
of a Segment/Road (from Point A till Point D) with the TMC Points unblocked.
Please tell me if I am wrong.

With the new tagging system there is no difference between a way which is part
of a TMC Point (eg roundabout or junction with several slip roads). In your wiki
example of the roundabout let there be a small road intersect from the
northeast. In order to get there comming from Point 7 you need to turn at the
roundabout about 300° and using part of (20+8) and (20-5). Would this still work ?

>> 5) Versioning
>> You argue that versioning is not needed, since data can be changed in a timely 
>> manner, and the errors that appear are mostly harmless. I don't feel that way:
>> a) Experience tells that data is not always changed in a timely matter, 
>> especially since TMC data does not appear on most of the maps. It takes a 
>> while to process data (being half a month outdated seems to be normal even for 
>> online routing), and offline maps make this situation worse (just look at the 
>> bug reports at MapDust that appeared since Skobbler had started shipping offline 
>> maps).
>> b) When LCDs are inserted into chains, things break *badly*, since the extents 
>> are then out of sync as well.
> Since TMC tags will simply be part of all other road network data that any
> solution will use for mapping, navigaiton, etc., they will always fit together
> from the time of creation. So there's n need for versioning. On the other hand,
> it is abolutely certain that the issueing organisations that are in charge of
> TMC (like BASt in Germany) will never "re-cycle" previosly used location codes
> in a way that  might create trouble.

In my region there was and still is TMC data of the future available (version
9). This is due to changing routes and up/downgrading parts of the road system.
The decision was made before the (re)constuction was finished. E.g. TMC data
leads along roads with heavy constuctions or even non existing roads and was/is
inconsistant with the routes on the ground (traffic signs). With the versioning
I was able to tag the current (old) route and the future one.

> Best regards,
> Mit freundlichen Grüßen,
> Heinrich Knauf

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