Hi, it's a good thing that someone finally tries to clarify access documentation - it definitely needs some care. I agree with your reasoning to replace the image with editable content and some of your definitions (such as avoiding to put an entry into the hierarchy multiple times and separating water/land).
Nevertheless, some changes require a bit of discussion, but I guess you expected this, didn't you? ;) Christiaan Welvaart wrote: > Added a separate tag for cars, because AFAICT any routing app computing > routes for cars uses this transportation mode. If routing would be done > for 'motorcar', ways tagged as hazmat=no, for example, could not be used > because the motorcar *could* be a hazmat vehicle. This reasoning is not quite valid. The restrictions for a vehicle category are affected by categories higher up in the hierarchy, not by those below. At least this is the idea behind current documentation such as http://wiki.openstreetmap.org/wiki/Computing_access_restrictions , and I don't see why we should be restricted to leaves of the category tree. Therefore, considering an automobile a generic "motorcar" that is affected by those restrictions applying to generic motorcars should work well, it doesn't need an own category. > * Direction specific restrictions > > I listed :backward and :forward postfixes for access keys What you are doing here seems like picking raisins from conditional tagging and trying to handle it as a special case. I'm not sure whether you are aware of my proposal? http://wiki.openstreetmap.org/wiki/Proposed_features/Conditions_for_access_tags While direction may be considered as something special when constructing a routing graph (unlike most other parameters it will have different values during creation of the same routing graph; unless you are really sophisticated and use changing time, it will be the only parameter like this), it's not a special case for *evaluation*: It's just another parameter needed to get the value of a base tag for the current situation. As evaluation is the aspect that needs to be documented (routing graph creation is up to the application), I believe forward/backward shouldn't be introduced or documented separately but instead as a part of conditional tagging. > * Evaluating access tags Your use of "category" and "(transport) mode" confuses me, especially as they both seem to be things that can be a key. I know from experience that it is hard to find good terms for these concepts, but maybe you can help me a bit to understand it. Tobias Knerr _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk
