Garmin Edge 705 bug in bicycle routing
Hi all, I just updated http://wiki.openstreetmap.org/wiki/Mkgmap/routing/issues#Bad_bicycle_routing with an example where the bicycle route from A to C is much longer than the routes from A to B and B to C. I guess but have not verified that this is because of an access restriction that I added near B. It seems that the routing engine in Garmin Edge 705 ignores cycleways in the middle of the route on longer routes. If bicycling is prohibited on the major road, then you may be sent to a long detour, ignoring the cycleway running next to the major road. I may check this later, by temporarily reverting the bicycle=no on a section of the major road. I still have a copy of the finland.osm that I used for the test. Marko
Just a thought, is it related to the zoom level of the cycleway as set in the style file? What happens if you make the cycleway have the same zoom level as the road next to it?
Marko Mäkelä schrieb:
http://wiki.openstreetmap.org/wiki/Mkgmap/routing/issues#Bad_bicycle_routing
with an example where the bicycle route from A to C is much longer than the routes from A to B and B to C. I guess but have not verified that this is because of an access restriction that I added near B. It seems that the routing engine in Garmin Edge 705 ignores cycleways in the middle of the route on longer routes. If bicycling is prohibited on the major road, then you may be sent to a long detour, ignoring the cycleway running next to the major road.
Did you check, if the online routing services are able to route bicyclers correct on this location? Maybe some missing link from the main road to the cycleway? But indeed: the garmin bicyle routing is a little bit mystic. That's the reason for me using "taxi" in my style for bicyle routing. Chris
Hi Mark, Chris, all, Sorry, I was wrong about the bicycle=no. I removed the bicycle=no, foot=no in a local copy of the tile, and it did not affect the suggested routes. This is within a single map tile. mkgmap spits out some "zero length arc" warnings, but none should be on this route. java -ea -jar mkgmap.jar does not fail. On Tue, Aug 25, 2009 at 01:20:15PM +0100, Mark Burton wrote:
Just a thought, is it related to the zoom level of the cycleway as set in the style file? What happens if you make the cycleway have the same zoom level as the road next to it?
I tried raising the resolution from the default 23 to 19, but it only affected the map display (I'm able to see cycleways above 130m zoom levels). On Tue, Aug 25, 2009 at 03:01:08PM +0200, Chris-Hein Lunkhusen wrote:
Did you check, if the online routing services are able to route bicyclers correct on this location? Maybe some missing link from the main road to the cycleway?
I validated the whole route based on track logs I recorded last week on a bicycle ride (2*160 km). I did fix some errors and omissions, and the map extract should include all my fixes. Besides, the routes from A to B and B to C are just fine, just ignoring some cycleways that ran in parallel to the highway 140. It is the route from A to C that is nonsense, making a detour off highway 140. (A=Jokivarsi, B=Heinola, C=Kuortti.) I updated http://wiki.openstreetmap.org/wiki/Mkgmap/routing/issues#Bad_bicycle_routing with this info.
But indeed: the garmin bicyle routing is a little bit mystic. That's the reason for me using "taxi" in my style for bicyle routing.
I prefer to stick to the standard types. Besides, the Edge 705 only offers three major routing modes: car/motorcycle, bicycle, and pedestrian. Minor modes include "avoid unpaved roads", "avoid toll roads", "avoid highways". To summarize, this just a demonstrates a deficiency in the routing algorithm of the Edge 705. It is probably impossible to get bicycle routing work right by tweaking the maps alone. Generally, I have found the route suggestions useful for bicycle rides up to 30 km in urban areas. Best regards, Marko
To summarize, this just a demonstrates a deficiency in the routing algorithm of the Edge 705. It is probably impossible to get bicycle routing work right by tweaking the maps alone. Generally, I have found the route suggestions useful for bicycle rides up to 30 km in urban areas.
Personally I find the bicycle routing on my 605 bizarre. 10km diversions just to avoid going onto an A road, being sent down tracks when there are residential roads available etc. It seems that the lowest category path is the best one as far as the bike routing engine is concerned. In very well mapped urban areas I dare say that it's passable but in less well mapped areas it's just plain daft Cheers Paul
participants (4)
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Chris-Hein Lunkhusen -
Mark Burton -
Marko Mäkelä -
Paul