David Was there a specific purpose you had in mind that needs to distinguish between the main span of a bridge and it's ramps, or were you just exploring the level of consistency in current tagging practices?
I wonder if we are approaching this problem from the right direction. There are currently about 250,000 ways that are tagged bridge=yes. Since there's no generally agreed definition of the extent of a bridge every user will have used a different assumption and their own judgement. Perhaps we should keep the vague and approximate definition that the bridge tag provides, and instead propose extra tags that more precisely define the lesser characteristics of a bridge. The bridge tag as it currently exists, for all its vagueness, is easy to use and effective. For more precision we could consider additional tags that precisely define the individual parts of a bridge. The addition of a bridge_ramp tag, for example, could be used to indicate whether or not a bridge includes or excludes the ramps. bridge=yes, bridge_ramp=included|excluded For those that want to define the extent of the ramps specifically then a separate way would be required for each ramp and for the main span, perhaps like this: bridge=yes, bridge_ramp=yes bridge=yes, main_span=yes bridge=yes, bridge_ramp=yes However, I'm not sure such an elaborate scheme would catch on much unless there's a real benefit in tagging bridges to a greater level of detail. That's why I wondered whether you have a specific reason for wanting to tag bridges with more precision. 80n On Thu, Jan 22, 2009 at 8:21 PM, Matthias Julius <[email protected]>wrote: > Chris Hill <[email protected]> writes: > > > A bridge is usually there to cross something. So I would say, > > generally, what ever was built or built-up or added to make the bridge > > function is part of the bridge. So ramps or approaches on embankments > > even might well be judged to be part of the bridge. Maybe a note > > attached to briefly describe your decision will help future OSMers. As > > always there are exceptions. > > I'd day when there is air under the road it is part of the bridge, if > there is only a pile of dirt it is not part of the bridge. Even if > the dirt has been specifically piled up there to be able to get on top > of the bridge. > > Matthias > > _______________________________________________ > talk mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/talk >
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