Javbw
> On Nov 26, 2015, at 6:18 AM, Philip Barnes <p...@trigpoint.me.uk> wrote: > > adding parallel ways which do not exist on the > ground. Sidewalks are parallel ways with very different access restrictions that exist on the ground - so I'm not sure what you mean. I can easily see them and their crosswalks and bridges in arial imagery. Sidewalks accompany a road - but cars on sidewalks and people in the center of roads is a very bad thing, right? Frontage roads often accompany train tracks, but the frontage road is not an attribute of the track. Both sidewalks and frontage roads have different routing, different grades of construction, disappear and reappear, and have different access restrictions. They are *separate*. Roads and sidewalks often have heavy barriers between the road and the sidewalk. A kerb is a very big barrier to a wheelchair. A fence, bollard, hedges, *planter boxes, walls, bridge pilings, guardrails, and other barriers exist on urban areas to physically separate the road from the sidewalk, but for certain people (wheelchairs) a kerb can be just as effective a barrier as a wall. [*I need to create that barrier value] Sidewalks can end when a road continues. Sidewalks can have width restrictions and hazards (poles, walls, etc) that affect the sidewalk but not the road. The sidewalk can have different routing (into a park or under a bridge with steps) rather than using the same paths as the road. They may not share intersections with a road (bypass over it via footbridge). Sidewalks can have different surfaces, which change much more rapidly than the road does. What if it's different on one side of the road from the other ? We will need to keep tagging the road with "foo:sidewalk:left=*" and "foo:sidewalk:right=*" to keep everything straight? All of this could be done by adding tags to the road, but wow! The segmentation that would occur! I don't care so much, but people running relations would. How would I show where a crosswalk or footbridge intersects - which is a separate way from the road but not the sidewalk??? What a giant, complex pile of newbie-nuking tag-salad! Or we can draw a way where the sidewalk is and dump all that tag complexity onto it, completely separate from the road and it's attributes - and the sidewalk on the other side, let alone the poles and barriers and vending machines and bus stops and driveways and kerbs and all the other stuff - beyond buildings and driveways - that is easily mappable (and is being mapped) in urban imagery that exists somewhere around the sidewalk and the road. It belongs on a separate way where imagery is good enough and when mapping time allows. Sidewalk=left/right/both on a road is a great stop-gap until better imagery is available and better mapping can be done - but by no means is sufficient in any dimension whatsoever for proper foot routing in urban envrons, which is where like 90% of foot routing is going to take place. Getting that last 500m from the train station to the destination can be a totally and completely different. Proper routing of each depends on proper tagging of each separate route, for ease of use, safety, and access restriction reasons. Javbw. _______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
