>> TIGER obfuscates the data by declaring the entire numbering range of a >> zone: for example a "400 block / Even" containing houses 404 through 420 >> would be declared as "range Even / 400-498" in TIGER. For navigation >> purposes, that gets you to within one block of an address. > > Maybe they do it for obfuscation, but that has the additional > advantage of being able to locate an approximate address when house > #422 (or #402) gets added to the block. Of course, we don't have to > be quite as dumb as Tiger. We could always use three blocks, > 400-404/Even, 404-420/Even, and 420-498/Even.
Why use 3 blocks? If a cursory survey shows that 404 and 420 are physically the endpoints of a block, why not use a single way? Even if 420 is not the physical endpoint, why not a single way? > It's not quite the same idea, though. The Karlsruhe Schema maps > actual addresses, at the house location. The Tiger Schema (for lack > of a better name) maps potential address ranges, at the street > location. They both have their uses: If a house is located far away > from the actual street, you would certainly want to use something like > the Karlsruhe Schema. If you have no idea where the house is (or is > going to be) located other than its relation to a street, you would > want to use the Tiger Schema. Arbitrarily sticking a way some > distance to the right or left of a highway, in order to coax > street-level data into a house-level schema, would be inappropriate. What is a house number after all, if not street-level data? The house number has no meaning to the physical building if not attached to a street. I still perceive the Tiger Schema as a variation on the Karlsruhe Schema - the only difference is the estimated accuracy. > And that's just the easy case, when you're not trying to combine data > from both schemas on the same block (I'm not sure that any of these > have been mapped yet, but imagine a rural area with lots of houses > near the road, some houses far off the road in flag lots with long > driveways, and some houses both on and off the road in various stages > of development and not yet assigned addresses; or try to combine > actual addresses and potential addresses on a road in a retail area > with lots of strip malls with individually addressed stores; or a road > with lots of apartment complexes/condos with individually addressed > apartments/condos). I would never use the Karlsruhe Schema ways to determine a house/building location. There can be many good reasons to use address interpolation when the building location is unknown - no aerial photographs, blurred or obstructed aerial photos, new construction, etc. >> Now imagine if they were asked to check >> the address relation: "Go into edit mode, check the way the arrows point >> on >> your street, inspect the left / right roles to be sure that the house >> numbering is correct". > > For clarification, the direction for the purposes of right/left would > be determined by the start and end node, not the direction of the way. > The way could be reversed without breaking anything (and not all the > ways have to even go the same direction). Now I'm confused. Unless the street is one-way, the only way to find the start and end node is to go into edit mode. Streets can be oriented in any direction, so left/right is often not useful for physical representation on the map. _______________________________________________ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
