[OSM-newbies] Updating info for an old Tiger road

[Todd D. Taft]

On 8/30/14, 8:27 PM, Mike N wrote:
> On 8/30/2014 8:15 PM, Doug Hembry wrote:
>> highway=residential. But on the ground today, the roads have
>> deteriorated into tracks, maintained as fire roads and for recreation.
>> The road name has fallen out of use (no road signs, and trail names
>> often different from their old road names). How to handle this? Do all
>> the old Tiger tags go? Does the name= tag go? It seems a pity to discard
>> the old information about what these tracks/roads once were - they are
>> pertinent to understanding the historical record of the region, even if
>> the renderers don't use such information. Is there some way to modify
>> the old tags as no longer current, but leave them in place?
>
>   Update the way information to reflect its current state.  Tiger tags 
> are not important for that case: they may all be deleted. 
> OpenstreetMap retains the history of the way, so the current 
> information will not be completely discarded in any case.
>
While you are technically correct that information about deleted tags or 
even entirely deleted ways remains in the database, it's somewhat 
difficult to access this data in many rendering engines. Unless the 
change has a good change note, it's often hard to know why something got 
changed.  Did the old values reflect a reality that existed at some 
point in the past, but conditions have changed such that properties need 
to be updated, or were the old values wrong in the initial database and 
thus never actually reflected reality?

There are some tags that I'll list below that could be used to maintain 
information about the former state of these roads in such a way that 
indicate that conditions have changed.  In (the default configuration 
of) most rendering engines, these tags would not affect how the way 
appears in map view, but they would still appear if someone selected the 
way and viewed the tags.

I would agree that the primary tags should be updated to reflect the 
current status of these former roads.

The old_name tag ( http://wiki.openstreetmap.org/wiki/Key:old_name ) 
would be a way to preserve the former names of these roads if they now 
have different names.

I would suggest that you look at the disused and abandoned name spaces 
to describe the former roads, especially in the cases where the former 
roadway still exists in some other form (e.g. path).  See 
http://wiki.openstreetmap.org/wiki/Key:disused and 
http://wiki.openstreetmap.org/wiki/Key:abandoned for a more complete 
description.

If no trace of a former object exists, I have usually seen the node or 
way deleted; however, there are some other potential ways of dealing 
with these situations.  See 
http://wiki.openstreetmap.org/wiki/Key:end_date or 
http://wiki.openstreetmap.org/wiki/Historical_OSM for more information.  
Note that there are many unresolved issues and some controversy 
regarding keeping objects that no longer exist in OSM.

-- 
Todd D. Taft
taft at unclet.net