[mkgmap-dev] motorway_link not always oneway

Wed Oct 27 11:57:55 BST 2010

On Tue, Oct 26, 2010 at 11:27:27PM +0200, Martin Simon wrote:
>> PS: Any objections if the default style adds surface=paved to 
>> motorways and motorway links? What does the Vienna convention say 
>> about motorways? Does it require a paved surface?
>
>No, not from my side. IMHO, there is quite a difference between 
>"dictating" global or per-country defaults for highway types and 
>interpreting data when reading it with a tool like mkgmap.

On a second thought, the default style would not benefit from the 
surface=paved. There are two rules with { add mkgmap:unpaved=1 } and 
none that would set mkgmap:unpaved=0, because mkgmap:unpaved=0 is the 
implicit default.

>IMHO, the best thing to happen for the database would be tools like 
>mkgmap ignoring top level highway tags to some degree (lets say 
>reducing them internally to 
>pathlike->tracklike->normalroadlike->connectingroadlike->motorwayroadlike) 
>and focusing on the secondary, more specific tags like surface, lanes, 
>width, sac_scale, "grade_seperated" etc. to determine the 
>sub-categories and routing importance.

That could make sense for motor vehicle routing in densely built areas, 
yes.  Bicycle and pedestrian routing is hopeless beyond distances 
greater than a few km, because the Garmin algorithm takes unacceptable 
shortcuts (ignoring all cycleways or paths in the middle of the route).

	Marko