Proposed features/implicit maxspeed

From OpenStreetMap Wiki
Jump to navigation Jump to search
implicit maxspeed
Status: Draft (under way)
Proposed by: RubenKelevra
Tagging: maxspeed=*
Applies to: ways
Definition: implicit maxspeed values in the maxspeed tag
Statistics:

Drafted on: 2021-09-07
RFC start: TBA
Vote start: TBA


Proposal

The long-standing definition of the maxspeed-tag has recently been changed by habit quite a bit. In some countries implicit values, following the scheme maxspeed=<countrycode>:<zone type> has been widely used.

This proposal aims to rectify the fact that we now have four different ways to tag an implicit speed limit - which leads to conflicting redundant information and is hard to parse and maintain.

This proposal, if accepted, will deprecate and discourage the use of maxspeed:type=*, source:maxspeed=*, and zone:maxspeed=* for implicit maxspeed zone tagging in favor of implicit values to be used in the maxspeed-tag itself.

This proposal aims to redefine that a number in maxspeed=* is meant to represent an explicit fixed speed limit by a signpost at the beginning of the stretch of a road. If there's an area to which the maxspeed applies, like a city or a slow speed zone, an implicit tag value e.g. (DE:urban and DE:zone:30) will be used instead of numeric values in the maxspeed=* tag.


Rationale

This proposal is meant to streamline the tagging, ease the parsing and avoid conflicting information by redundancies in the three other approaches.


Tagging

The current list of implicit values applies and the definition will be kept up to date in the maxspeed-article in the future.


A machine readable form is also available in the article Default speed limits. There's a parser available to read it. (thanks westnordost for the hint)


Examples

See the current maxspeed article Examples.

Features/Pages affected

The following features, if the proposal gets accepted, will be deprecated and the pages modified to explain the discouraged use of those tags for tagging implicit maxspeeds.

External discussions

westnordost explains in this post how StreetComplete is currently unable to resurvey the maxspeed feature with the conflicting tagging schemes and why there's a need for a new simpler way to tag this information.

Comments

Please comment on the discussion page.