[Talk-us] Removing tiger:* tags

[Nathan Edgars II]

On Fri, Jul 30, 2010 at 8:44 PM, andrzej zaborowski <balrogg at gmail.com> wrote:
> On 31 July 2010 02:33, Nathan Edgars II <neroute2 at gmail.com> wrote:
>> On Fri, Jul 30, 2010 at 8:28 PM, andrzej zaborowski <balrogg at gmail.com> wrote:
>>> I don't see how it changes anything.  If a piece of interstate I-405
>>> is described by one relation or two ways one for each carriage in osm,
>>> and 10 segments in TIGER, than that's a way to describe it.
>>
>> So how would you do any of the applications described above? They all
>> require either a single TLID or everything to be tagged with a field
>> that includes the correct TLID (due to joining, splitting, and
>> redrawing, the latter is not true).
>
> So your program tries to come up with a route, it knows it's driving
> on road A in osm.
> A has id=1 and is tagged "tiger:tlid=20:21:22:23", and it is connected
> to road B (id=2, tiger:tlid="24:25:26:27") by node id=3.  You also see
> that tiger way 23 meets 24.  That clearly means that from osm road A
> you can go into tiger way 24 when you reach node id=3, without even
> looking at the geometry and fuzzy guessing things (remember routing
> works on huge graphs).

But road A has been rerouted since the TIGER data was created and now
ends at road C, without touching road B. You can't use shortcuts like
this.

Or am I misunderstanding your example? If you already know A and B are
joined at node 3, what do the TLIDs tell you?
>
> Or say that the government releases a database that says how many
> traffic signals there are on each segment of road.  Then you can find
> the junction nodes on which they should be in OSM, or at least count
> how many there should be on a given street.

TLID 24 has two lights and TLID 25 has three. Joined TLID 24;25 might
have four or five. Add one to the possible error for each new segment.
Then split out bridges and it becomes unmanageable.
>
> And yes, street names are not 100% correct or complete in OSM today..
> we don't remove them though.

So are you saying you or someone else will be checking all TLIDs
against the TIGER data and correcting errors and adding missing ones?