[mkgmap-dev] Omitting ref from named minor roads

Thu Apr 7 13:50:36 BST 2011

On Thu, Apr 07, 2011 at 07:41:56AM -0400, Greg Troxel wrote:
>I don't follow how your patch preserves the old behavior on 
>secondary/primary/motorway.

For them, the name is set earlier, using specific rules that add the 
Garmin control codes for the oval and box symbols.

>I'm assuming that there are some roads that have reference numbers in 
>county road maintenance databases, but they aren't posted and only 
>serious road nerds know about them.  That's not true in my state, or if 
>so they are really not well known.
>
>I have been in Virginia and seen 4-digit route numbers in use (in 
>directions given to me, and on signs).  The roads were probably 
>tertiary.

Same here: at most 4-digit road numbers are usually posted, and I would 
consider them tertiary or secondary roads. Many tertiary roads 
(especially in cities) do not have any ref posted on road signs.

Someone on the Finnish forum posted that highway ramps have 6-digit 
numbers. :-) That was in response to my comment that someone had 
apparently copied the motorway_exit node ref to the exit ramp way.

>I don't object to your change, but this feels like a shortcut rather 
>than the right behavior.  The route reference should show up if it's 
>useful to the user, which is a cartographic decision.  We have a vector 
>database, but it makes sense to encode there where a route reference is 
>user-facing or merely administrative.  That's not rendering per se, but 
>a fact about the world that's legitimate to tag.  But, it's harder.

It may be useful for road nerds to have the official 5-digit or 6-digit 
refs for ramps or cycleways in the database, but I do not think that 
they can be useful for a Garmin map user. A road nerd user can always 
tweak the mkgmap style. :-)

My patch only affects the case when a minor road carries both a name and 
a ref. In that case, we would only display the name, not the ref.

	Marko