OpenHistoricalMap/Tags/LifeCycle
Introduction
This is a draft proposal on a way that OHM might go forward with lifecycle tagging. It is not an official document, but rather intended as a vehicle for discussion.
Premise
There will be a base set of nodes and ways, with tags that represent aspects of the entity that do not change over their life. They may be grouped by higher level relations containing lifecycle tags, with start and end dates. Things that might appear are indications of changing use. For example, Harmony Mills in Cohoes, New York, was built as a textile manufacturing facility. Later in its history, parts of building 3 were rented out to various commercial businesses. In its current state it is now residential loft apartments. There would relations with start/end dates for each of these periods.
Additional Lifecycle Elements
- construction=yes
- disused=yes
- abandoned=yes
- open=yes (or active=yes?, default if all tags of this type omitted?)
- foundation=yes
- ruin=yes
- others?
In this concept, disused could also be used to represent periods where one use has ended and another has not yet begun. This could also be between the end of construction and the first opening date. In the Harmony Mills example, disused during idle periods, and construction could be re-instituted during conversion from industrial to residential.
Alternate Lifecycle Approach
The previous concept extends the existing construction=/disused= tagging conventions of OpenStreetMap. Given that to a degree these options are mutually exclusive, the following approach may make sense:
- lifecycle=[construction|disused|abandoned|open|ruin|...]
Relation Type Extensions
Overloading OHM relations
Certain OHM relation types such as route lend themselves to handling lifecycle issues by adding start and end dates; for example, if a state highway has changed its routing over surface roads and streets over time, a route relation can be created for each version with start and end dates specified.
type=ohm:lifecycle
This would be for use where there are no suitable OSM relation types that can be overloaded with lifecycle data.
A generic Group relation type could work. There is a proposal in progress in OSM at this time although it seems inactive Proposed features/Group Relation. If this proposal were to succeed it would serve the purpose.
Lifecycle Laboratory
Lifecycle experiments are currently being done at two sites in upstate New York - the Crescent Dam site on the New York State Barge Canal between Cohoes and Crescent NY, and Harmony Mills in Cohoes NY.
Lifecycle Features in This Area
- Mohawk River - before and after construction of dams and locks
- Crescent Dam - three dams, several powerhouses
- Harmony Mills - 4+ buildings built over time and repurposed
- Segments of original and enlarged Erie Canal
https://www.openhistoricalmap.org/query?lat=42.78248&lon=-73.70605