User:Impiaaa/Hierarchical access
This page is some notes on what could become a new relation type to describe complex access relationships. Read the examples to get an idea of what this could apply to.
Tags
Key | Value | Explanation |
---|---|---|
type | access (conflicting with existing usage! TODO find a better name) | This is an access relation |
access | * | Used to describe access restrictions only if it cannot be described in the tags of either member |
Members
Way or Node | Role | Recurrence? | Explanation |
---|---|---|---|
accessfrom | one | The object that describes prerequisite access | |
accessto | one or more | The object that requires access from the accessfrom |
Examples
Picture | English description | Tags | Benefits over current schema |
---|---|---|---|
Link | ATM inside a bank inside a grocery store inside a shopping mall |
ATM Relation #1 Bank Relation #2 Grocery store
Relation #3 Shopping mall |
|
Post drop box accessible when the enclosing post office is closed |
Mailbox Post office No additional relations, or |
The mailbox can be a node within an area for the post office building. Geometry-based access checking would fail without mapping the post office indoor area separately, or displacing the mailbox node. | |
Link | Customer-only parking |
Parking Relation Shop
|
The mentioned "customer" is obvious--routing and searching can act appropriately, depending on user intent. |
Shops behind security checkpoint in airport |
Shop
Relation Security checkpoint
|
No need for indoor mapping, or re-appropriating access=permit. |
Prior art
Relations/Proposed/Provides feature
Undocumented, seems to cover the same cases, but specifically for roads
Misspelling
Undocumented, conflicting name, seems to be a "group" relation, to apply access tags to all members
Tag:amenity=cafe#Cafes inside other shops / amenities
Rationale
All of the examples above can be expressed in the current schema, but only in a limited way. Currently, in order to communicate the relationship in the first example, all 4 objects would have to be indoor-mapped with corridors and appropriate entrances, no overlapping areas, and opening_hours=* on all 4. Without successively shorter opening_hours=*, a search engine wishing to filter out currently inaccessible locations would have to include a full routing engine to make that determination. Alternatively, a search engine could check for enclosed geometry, but this requires a geometry processing step that is out-of-scope for a search engine, and would fail for the postbox example. This proposal communicates complicated object relationships in a straightforward way and without needing to do complex mapping.