Author Topic: Bridleways And Trails ?  (Read 1791 times)

Bridleways And Trails ?
« on: September 20, 2010, 07:21:31 pm »
I'm currently touring around West Sussex,  using an Etrex And OSM.  Several times now I've asked it to work out a route and it's routed me onto a bridleway.  I've told it I'm a delivery, I've told it I'm a bus!  Same result.

I've ticked the option to avoid unpaved roads, no difference. How can I stop it doing this ?
   
Not fast & rarely furious

tweeting occasional in(s)anities as andrewxclark

frankly frankie

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Re: Bridleways And Trails ?
« Reply #1 on: September 20, 2010, 11:09:14 pm »
If this was a question about Windows, someone would leap in and say "install Linux instead".

So in similar unhelpful vein, I'm going to suggest two options - install City Select instead, or, tour round East Sussex instead.

Some people seem to get routing with OSM to work, but I just think they're, well, either very lucky or very easy to please.
It's not dark yet but it's getting there.

Re: Bridleways And Trails ?
« Reply #2 on: September 20, 2010, 11:13:45 pm »
DOn't use OSM, seems it's data is wrong

fuaran

  • rothair gasta
Re: Bridleways And Trails ?
« Reply #3 on: September 20, 2010, 11:17:53 pm »
Yes, if its set to bicycle then you might get routed along paths/tracks etc, but I've never had that if its set to car/delivery/bus etc with standard OSM maps.

What OSM maps are you using?
If you're using something like Openmtbmap, which is designed specifically for off road cycling, it will route you along paths even if its set to motorcar.

Or any specific locations where this has happened? I could check to see if there's anything strange with the OSM tagging.

Re: Bridleways And Trails ?
« Reply #4 on: September 21, 2010, 08:06:35 am »
It's Andy's tweaked version installed from here.  Not happening all the time but enough to be annoying.

I'm not adverse to a spot of rough stuff , but not on a loaded tourer...
Not fast & rarely furious

tweeting occasional in(s)anities as andrewxclark

andygates

  • Peroxide Viking
Re: Bridleways And Trails ?
« Reply #5 on: September 21, 2010, 09:09:57 am »
Is it a specific bridleway, or any old bit of bridleway?
It takes blood and guts to be this cool but I'm still just a cliché.
OpenStreetMap UK & IRL Streetmap & Topo: ravenfamily.org/andyg/maps updates weekly.

Re: Bridleways And Trails ?
« Reply #6 on: September 21, 2010, 10:17:45 am »
Part of the problem with any of these systems is the data, or rather its simplification.

Think of a printed OS map with all te different levels of road, metalled, unmetalled, widths etc... and then about how much memorythis would take.

As a result the digital mappers tend to lump the road types into bigger groups, with the result that say yellow and white OS map roads become the same.

For this reason sometimes an unsuitable road will appear onthe route because of this data reduction.

Re: Bridleways And Trails ?
« Reply #7 on: September 21, 2010, 10:27:24 am »
I find OSM's fine for pre-planned routes which is what I use GPS for 99% of the time but I wouldn't want to be highly reliant on it for routing on the fly. The one time I did that due to an unplanned rail line closure it got me to my revised destination successfully but suggested a couple of dodgy turns along the way that were so obviously dodgy that I ignored them (one so much so that I couldn't even see what it was trying to take me up, not even a path through a field).

Wowbagger

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Re: Bridleways And Trails ?
« Reply #8 on: September 21, 2010, 10:38:15 am »
OSM has much more data than the proprietary brands. Most footpaths & bridleways simply aren't marked on Citimaps. Some are, and the machine sometimes interprets them as roads.

I'd try to avoid getting the Garmin to do your navigating for you no matter what your route. I accept that it's not always easy, but if I want the Garmin to navigate for me, I do it on a village-by-village basis, keeping the route down to 5 miles or less.
Oh, Bach without any doubt. Bach every time for me.

andygates

  • Peroxide Viking
Re: Bridleways And Trails ?
« Reply #9 on: September 21, 2010, 10:48:33 am »
Part of the problem with any of these systems is the data, or rather its simplification.

Think of a printed OS map with all te different levels of road, metalled, unmetalled, widths etc... and then about how much memorythis would take.

As a result the digital mappers tend to lump the road types into bigger groups, with the result that say yellow and white OS map roads become the same.

For this reason sometimes an unsuitable road will appear onthe route because of this data reduction.

Yes and no.  :)

I distinguish between yellow and white roads (as does OSM). 

But if a road is also a bridleway, then the mapper's preference comes into play: there's no easy way of drawing a highway and, say, casing it with bridleway-colour. 

Even so, bridleways ought to be being processed as vehicle=naughty_boy_no_stoppit so it could be down to my formatting choice.  The changes I made to fix the weird missing segments in Mapsource (which come down to ensuring that highways are processed before weirdways, as the processor just does the first thing it sees) may well have helped, so a fresh download is indicated. 
It takes blood and guts to be this cool but I'm still just a cliché.
OpenStreetMap UK & IRL Streetmap & Topo: ravenfamily.org/andyg/maps updates weekly.

Re: Bridleways And Trails ?
« Reply #10 on: September 26, 2010, 09:55:17 am »
Part of the problem with any of these systems is the data, or rather its simplification.

Think of a printed OS map with all te different levels of road, metalled, unmetalled, widths etc... and then about how much memorythis would take.

As a result the digital mappers tend to lump the road types into bigger groups, with the result that say yellow and white OS map roads become the same.

For this reason sometimes an unsuitable road will appear onthe route because of this data reduction.

Yes and no.  :)

I distinguish between yellow and white roads (as does OSM). 

But if a road is also a bridleway, then the mapper's preference comes into play: there's no easy way of drawing a highway and, say, casing it with bridleway-colour. 

Even so, bridleways ought to be being processed as vehicle=naughty_boy_no_stoppit so it could be down to my formatting choice.  The changes I made to fix the weird missing segments in Mapsource (which come down to ensuring that highways are processed before weirdways, as the processor just does the first thing it sees) may well have helped, so a fresh download is indicated. 

Wasn't meant as a criticism, more of an explanation.

I think as with anything else it is common sense, and not expecting to be spoon fed everything. Unlike this plonker:


Richard Fairhurst

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Re: Bridleways And Trails ?
« Reply #11 on: September 26, 2010, 11:41:44 am »
Non-automobile routing with mkgmap (the program used to produce Garmin .img files from OSM data) is a dark art, largely because Garmin don't really appear to have designed the eTrex's software for anything other than "big fast roads are good".

The mkgmap developers have performed pretty heroic efforts to tame it, but if you want to get cycle routing to work perfectly, you do have to invest a lot of brane cells into it... it's not just a matter of saying "compile this img with routing", which will seemingly work but won't always give the greatest routes.

As it happens, some of the mkgmap defaults seem to have been patched in by a rather obnoxious German MTB map compiler ( [mkgmap-dev] Bicycle routing improvements (reverting breakage from   r1431)
   
is an example of his style) and I strongly suspect that the "mmm, bridleway" routing may well be something to do with that.

It's nothing to do with "routing with OSM" or "it's data is wrong" - it's an mkgmap thing. That said, I would encourage people adding bridleways to OSM to also add a surface tag ("surface=gravel", "surface=grass", "surface=mud", "surface=you're 'avin a laugh", that sort of thing), which should enable smarter routing for those of us without Mr Obnoxious German's MTB proclivities.
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Panoramix

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Re: Bridleways And Trails ?
« Reply #12 on: October 17, 2010, 09:56:36 pm »
Yes, the munky map has already tried to route me down some stairs. I did try to understand mkgmap but was not very successful, it just made me realise that Andy is a star!

Re: Bridleways And Trails ?
« Reply #13 on: October 18, 2010, 11:27:33 am »
The rendering by OpenMTBmap.org is impressive for differentiating tracks but it  depends on them being tagged correctly. 
I got a bit of surprise when I looked at an area I had mapped, and found several errors (mine). 
I will sort out my local area, but people have different priorities. 

andygates

  • Peroxide Viking
Re: Bridleways And Trails ?
« Reply #14 on: October 18, 2010, 11:49:11 am »
IIRC, OpenMTBMap is a grand example of specialization: the vehicle routing is quite broken.  Part of the Munkymap brief is a good-for-all map, so I can, eg,  both drive to my Audax and ride it.

Those bloody stairs.  I need to think those through.  They're a new line type, so maybe they're in a Garmin subclass of highways.  Hmm...
It takes blood and guts to be this cool but I'm still just a cliché.
OpenStreetMap UK & IRL Streetmap & Topo: ravenfamily.org/andyg/maps updates weekly.