[mkgmap-dev] Routing does not work since December.

Mon Aug 9 21:46:27 BST 2010

On Mon, Aug 09, 2010 at 09:45:33PM +0200, Valentijn Sessink wrote:
>Since r1431 (2009-12-10) bike routing has, IMHO and for my situation, 
>degraded. When I'm building biking maps for the Amsterdam region, I'm 
>using a style file from r1430.

Relying on bicycles for most of my transportation needs, I take this 
seriously. Let me try to reason what is causing the breakage.

r1431 changed the minimum resolution of a few items. I believe that it 
has been established that the resolution will not affect routing, as the 
routing will take place at resolution 24. It also changed the road_class 
or road_speed of the following:

junction=roundabout:
  road_speed=2 or 1 instead of 5,4,3,2
  road_class unchanged

highway=motorway:
  road_speed=7 instead of road_speed=6
highway=motorway_link:
  road_speed=2 instead of road_speed=3
  road_class=3 instead of road_class=4
highway=trunk:
  add bicycle=no, foot=no (these were not added previously)
  road_class=4 instead of road_class=3
highway=trunk_link:
  add bicycle=no, foot=no (these were not added previously)
  road_class=3 or 4 instead of road_class=3
  road_speed=2 instead of road_speed=3
highway=* & motorroad=yes:
  add bicycle=no, foot=no (these were not added previously)

highway=primary_link, secondary_link, tertiary_link:
  road_speed=1 instead of 2 or 3

highway=minor:
  road_speed=3 instead of 2
highway=unclassified:
  road_speed=3 instead of 2
  road_class=0 instead of 1

highway=living_street:
  road_speed=1 instead of 2
highway=service:
  road_speed=2 instead of 1
highway=path:
  road_speed=1 instead of 0
highway=road:
  road_class=0 instead of 1
  road_speed=1 instead of 2

>Please note that this is for the Netherlands (which has many, many 
>roads and and abundance of bicycle paths on OSM) and for bike routing, 
>which has it's peculiarities on it's own.

I seem to remember that someone (Felix?) mentioned that Garmin bicycle 
routing knows two values of road_speed: zero and nonzero. Before r1431,
highway=path and highway=cycleway got different road_speed: 0 and 1, 
respectively. Starting with r1431, both have road_speed=1. Could that be 
the source of the breakage? If it is (please test road_speed=0 on 
highway=path in the current default style), then I would change the 
default style so that highway=path & bicycle=(designated|official) gets 
road_speed=1 and all other highway=path get road_speed=0.

Best regards,

	Marko